diff --git a/.changeset/23789-page-props-save-door-sentences.md b/.changeset/23789-page-props-save-door-sentences.md
new file mode 100644
index 00000000000..9acc002a709
--- /dev/null
+++ b/.changeset/23789-page-props-save-door-sentences.md
@@ -0,0 +1,9 @@
+---
+'@objectstack/spec': patch
+---
+
+docs(spec): the step-18 upgrade text and the `exportOptions` TSDoc say a stored page's next save meets the component-props gate at the metadata save door
+
+Clause-②: no
+
+Text only; no accept set moves. Since the component-props gate (`validateComponentProps` / `validateComponentTypes`) runs on a `page` write at the metadata save door, three step-18 semantic entries that `os migrate meta` and the protocol upgrade guide print — `ui-page-action-row-operation-declared`, `ui-object-block-grouping-config-typed` and `element-text-variant-heading-subheading-retired` — and the `object-grid` `exportOptions` TSDoc in the `.d.ts` still said a page component's `properties` is not parsed on the save path. They now say what runs: a stored page still loads, because `properties` is not parsed on the metadata load path, and the next save of the page meets the component-props gate at the metadata save door (422 `INVALID_METADATA` on a finding), beside `os validate`, `os build` and `os lint`.
diff --git a/content/docs/deployment/cli.mdx b/content/docs/deployment/cli.mdx
index a85386649b4..24bbad1632c 100644
--- a/content/docs/deployment/cli.mdx
+++ b/content/docs/deployment/cli.mdx
@@ -1491,7 +1491,7 @@ can produce, because both supply a live one.
 | Rows that still fail the current schema after conversion | That is a genuine contract violation, not chain-owned history. The write path's rejection is correct; fix the row in Studio |
 | A flow whose rename the conflict guard refused | The old node-type token is a live name something else owns here. Rewriting would clobber that owner, so the row fails loudly naming the token — never a silent skip |
 | A site the conversion chain leaves as stored because no lossless rewrite exists — above all a page filter carrying `$and` / `$or` / `$not` | Flattening a combinator changes which rows the page selects, so it is never done. Each site is printed as a `TODO` line under its row — path, block, and what blocks the rewrite — whatever the row's outcome; a row with nothing but TODOs is reported `skipped`. It does not fail the run, since no run of this pass can clear it: rewrite each site by hand |
-| A stored shape protocol 18 refuses and no conversion rewrites — a `controlled_by_parent` object without exactly one required `master_detail` (two masters, none, a required `lookup` only, an explicit `required: false`), a view bound to the retired view-level API data source or a page component whose `data` prop binds it (`object-grid`, `object-map`, `object-gantt`, `object-tree`), a flow value slot carrying a `{…}` token (a `get_record` / `update_record` / `delete_record` filter operand among them) | Each would need a choice only its owner can make — which master, which page, what an absent value should do — so it is never rewritten. Each site is printed as a `TODO` line under its row, naming the step-18 entry that refuses it, the object, view, page component or flow node, and the owner's choices; a binding's request headers are withheld. Until it is rewritten by hand, the row is refused: an object registers but derives no master, a view registers under `[metadata_spec_invalid]`, a page still loads and saves while `os validate`, `os build` and `os lint` refuse the binding in source, and a flow is not registered |
+| A stored shape protocol 18 refuses and no conversion rewrites — a `controlled_by_parent` object without exactly one required `master_detail` (two masters, none, a required `lookup` only, an explicit `required: false`), a view bound to the retired view-level API data source or a page component whose `data` prop binds it (`object-grid`, `object-map`, `object-gantt`, `object-tree`), a flow value slot carrying a `{…}` token (a `get_record` / `update_record` / `delete_record` filter operand among them) | Each would need a choice only its owner can make — which master, which page, what an absent value should do — so it is never rewritten. Each site is printed as a `TODO` line under its row, naming the step-18 entry that refuses it, the object, view, page component or flow node, and the owner's choices; a binding's request headers are withheld. Until it is rewritten by hand, the row is refused: an object registers but derives no master, a view registers under `[metadata_spec_invalid]`, a page still loads, its next save is refused at the metadata save door (422), and `os validate`, `os build` and `os lint` refuse the binding in source, and a flow is not registered |
 | Any other site `registerFlow` refuses in a stored flow the parse accepts — a text slot's template hole, a decision's `mode`, a malformed predicate, a plugin node's undeclared config key, an `api` flow with no secret | The flow's own definition is wrong, and no conversion rewrites it. Each site is printed as a `TODO registerFlow` line under its row, in the words `registerFlow` refuses it with; a site already listed under a step-18 entry is not repeated. Until it is fixed, the flow is not registered at boot and never runs. A flow the parse itself refuses is reported among the rows that could not be rewritten, in the parse's words |
 
 **One thing it lists and never writes: decision nodes that changed meaning at
diff --git a/packages/spec/src/migrations/entries/semantic/18.element-text-variant-heading-subheading-retired.ts b/packages/spec/src/migrations/entries/semantic/18.element-text-variant-heading-subheading-retired.ts
index 676def812d8..e53613c7348 100644
--- a/packages/spec/src/migrations/entries/semantic/18.element-text-variant-heading-subheading-retired.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.element-text-variant-heading-subheading-retired.ts
@@ -32,10 +32,11 @@ export const entry: SemanticMigration = {
     + 'and `subheading` in a medium-weight small heading style, and `h2` / `h3` draw their own, larger '
     + 'styles. Whether the page wanted that level is the author\'s call — a heading placed for its '
     + 'size rather than its place in the outline may want a deeper level. Nothing is dropped at rest: '
-    + 'a stored page replays the rewrite at rehydration; a page component\'s `properties` is not '
-    + 'parsed on the save path, and the component-props gate reports an old spelling as a '
+    + 'a stored page replays the rewrite at rehydration and still loads, because a page component\'s '
+    + '`properties` is not parsed on the metadata load path, and the next save of the page meets the '
+    + 'component-props gate at the metadata save door. The gate reports an old spelling as a '
     + '`component-props-invalid` error, carrying the prescription, on `os validate`, `os build` and '
-    + '`os lint`. ADR-0087',
+    + '`os lint` and at that save door. ADR-0087',
   acceptanceCriteria:
     'No `element:text` page component carries `variant` `heading` or `subheading`; `os validate` '
     + 'reports no `component-props-invalid` finding under `properties.variant` for these blocks. For '
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-member-params-array-only.ts b/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-member-params-array-only.ts
index 188f4d8afc2..a57dfbd9dd1 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-member-params-array-only.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-member-params-array-only.ts
@@ -10,9 +10,10 @@ import type { SemanticMigration } from '../../types.js';
 // key, and #21704's fork 5 A refused the member's `properties.params`, so a
 // member has no static-values spelling and the container drops a non-array
 // `params` on any other type at run time. D3 only: page-component `properties`
-// is not parsed on the metadata save or load path, so a stored page is never
-// refused at load; there is no D2 conversion, because the only home for static values
-// is a different node (an `action:button`), which no rewrite can build in the
+// is not parsed on the metadata load path, so a stored page is never refused at
+// load (its next save meets the component-props gate at the metadata save
+// door); there is no D2 conversion, because the only home for static values is
+// a different node (an `action:button`), which no rewrite can build in the
 // author's place; and the census found no writer to respell.
 export const entry: SemanticMigration = {
   id: 'ui-action-group-menu-member-params-array-only',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-members-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-members-typed.ts
index 963f3d7c171..03ce9983499 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-members-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-action-group-menu-members-typed.ts
@@ -9,10 +9,11 @@ import type { SemanticMigration } from '../../types.js';
 // with the rows' prescriptions; `outcomeMessages`, a member `className` and
 // `properties.params` refused; `outcomeMessages` undeclared on all four action
 // blocks. D3 only: page-component `properties` is not parsed on the metadata
-// save or load path, so a stored page is never refused at load; and the authored census
+// load path, so a stored page is never refused at load (its next save meets the
+// component-props gate at the metadata save door); and the authored census
 // found no working member to respell — the refused values are objectui's probes
-// of the very reads the ruling refuses (a member `className`, `outcomeMessages`,
-// `properties.params`) and of the host's `autoTrigger` flag.
+// of the very reads the ruling refuses (a member `className`,
+// `outcomeMessages`, `properties.params`) and of the host's `autoTrigger` flag.
 export const entry: SemanticMigration = {
   id: 'ui-action-group-menu-members-typed',
   surface: 'page `action:group` and `action:menu` components — each member of `properties.actions` (whose keys '
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-block-grouping-config-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-block-grouping-config-typed.ts
index 8752a6f6e0a..c4c5a0cec14 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-block-grouping-config-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-block-grouping-config-typed.ts
@@ -42,9 +42,10 @@ export const entry: SemanticMigration = {
     + 'unpadded name silently equivalent, which is the consumer tolerance the contract refuses, '
     + 'and a bare string, a number or an empty list has no mapping that says what grouping was '
     + 'meant. Metadata AT REST is left exactly as stored — `properties` on a page component is '
-    + 'not parsed on the save path, so a stored page keeps loading and renders as it does today; '
-    + 'the component-props gate reports such a value as a `component-props-invalid` '
-    + 'error at the offending path on `os validate`, `os build` and `os lint`, a padded name '
+    + 'not parsed on the metadata load path, so a stored page keeps loading and renders as it does '
+    + 'today, and the next save of the page meets the component-props gate at the metadata save '
+    + 'door. The gate reports such a value as a `component-props-invalid` error at the offending '
+    + 'path on `os validate`, `os build` and `os lint` and at that save door, a padded name '
     + 'with the received value and the unpadded name to write. ADR-0049 / ADR-0087.',
   acceptanceCriteria:
     'Every `object-grid` and `object-kanban` node in your pages either omits `grouping` or '
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-custom-fields-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-custom-fields-typed.ts
index 2cf54c516b0..1c393aa0a2f 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-custom-fields-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-custom-fields-typed.ts
@@ -8,8 +8,9 @@ import type { SemanticMigration } from '../../types.js';
 // snake_case. The maintainer ruled on #21704 (fork 2, letter B) that the spec
 // declares a closed runtime form field of the members the form draws, in
 // camelCase, keyed by `name`. D3 only: page-component `properties` is not
-// parsed on the metadata save or load path, so a stored page is never refused at load;
-// and the authored census, with every inline option list evaluated, found no
+// parsed on the metadata load path, so a stored page is never refused at load
+// (its next save meets the component-props gate at the metadata save door); and
+// the authored census, with every inline option list evaluated, found no
 // working member to respell — the refused values are a type-level test's
 // `visibleOn` and a fixture pinning that an inline `defaultValue` seeds
 // nothing. The shipped object-manager dialog's options (`{ label: 'Box', value:
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-fields-names-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-fields-names-typed.ts
index a7264db5f32..ba7ea5b88b2 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-fields-names-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-fields-names-typed.ts
@@ -7,12 +7,13 @@ import type { SemanticMigration } from '../../types.js';
 // while the form drew a `{ name }` field entry its own page-builder guide
 // taught. objectstack-ai/objectui#11550 retired that entry from every authoring
 // face (the form still draws a STORED one, by its name, as tolerance), so both
-// rows now take field names — objectui's own declaration of the member — and
-// an object entry is refused with what to write instead. D3 only: page-
-// component `properties` is not parsed on the metadata save or load path, so a
-// stored page is never refused; and the authored census found no authored
-// value to respell — the refused values are fixtures probing the stored read,
-// the console warning and objectui's own refusal.
+// rows now take field names — objectui's own declaration of the member — and an
+// object entry is refused with what to write instead. D3 only: page-component
+// `properties` is not parsed on the metadata load path, so a stored page is
+// never refused at load (its next save meets the component-props gate at the
+// metadata save door); and the authored census found no authored value to
+// respell — the refused values are fixtures probing the stored read, the
+// console warning and objectui's own refusal.
 export const entry: SemanticMigration = {
   id: 'ui-object-form-fields-names-typed',
   surface: 'page `object-form` and `object-master-detail-form` components — `properties.fields` (whose '
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-members-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-members-typed.ts
index 573e0acb556..89b0104f32d 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-members-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-members-typed.ts
@@ -11,8 +11,9 @@ import type { SemanticMigration } from '../../types.js';
 // `z.unknown()` (the form draws a `{ name }` field entry and an inline runtime
 // field inside a section, which the typed shapes would refuse), and
 // `customFields` waits for the spec to declare objectui's runtime form field.
-// D3 only: page-component `properties` is not parsed on the metadata save or
-// load path, so a stored page is never refused at load; an off-shape value has no
+// D3 only: page-component `properties` is not parsed on the metadata load path,
+// so a stored page is never refused at load (its next save meets the
+// component-props gate at the metadata save door); an off-shape value has no
 // rewrite that says what the author meant; and the authored census found no
 // authored value to respell — the refused values are fixtures probing that the
 // form refuses them.
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-sections-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-sections-typed.ts
index c55cf19053d..38288fb63bc 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-form-sections-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-form-sections-typed.ts
@@ -9,8 +9,9 @@ import type { SemanticMigration } from '../../types.js';
 // 3, letter B) a page-block section shape of its own — the form view's section
 // keys plus the three entry arms the form reads, canonical spellings only — and
 // the stored form view is unchanged. D3 only: page-component `properties` is
-// not parsed on the metadata save or load path, so a stored page is never
-// refused at load; and the authored census, with every inline option list evaluated,
+// not parsed on the metadata load path, so a stored page is never refused at
+// load (its next save meets the component-props gate at the metadata save
+// door); and the authored census, with every inline option list evaluated,
 // found no working section to respell — the refused values are the two probes
 // in objectui's `formSectionGroupReference-7051.test.tsx` (a section declaring
 // neither `fields` nor `group`, and a group-owned `label` / `collapsible`
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-gantt-markers-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-gantt-markers-typed.ts
index 7c2edacd364..f33f1384c47 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-gantt-markers-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-gantt-markers-typed.ts
@@ -2,17 +2,18 @@
 
 import type { SemanticMigration } from '../../types.js';
 
-// #21464 — the `object-gantt` page block's `markers` was `z.array(z.unknown())`:
-// its element contract lived only in objectui, so a marker with no `date`, a
-// numeric `date` or a misspelled member passed the component-props gate, and
-// the chart drew no line, or drew it unlabelled and in the default colour. The
-// spec now declares objectui's own authoring declaration of a marker,
-// `{ date, label?, color? }` with `date` a string, and the row takes it. D3
-// only: page-component `properties` is not parsed on the metadata save or load
-// path, so a stored page is never refused at load; a misspelled member has no rewrite
-// that says which of the three the author meant; and the authored census found
-// no authored value to respell — the one refused value is objectui's own
-// compile-time refusal probe.
+// #21464 — the `object-gantt` page block's `markers` was
+// `z.array(z.unknown())`: its element contract lived only in objectui, so a
+// marker with no `date`, a numeric `date` or a misspelled member passed the
+// component-props gate, and the chart drew no line, or drew it unlabelled and
+// in the default colour. The spec now declares objectui's own authoring
+// declaration of a marker, `{ date, label?, color? }` with `date` a string, and
+// the row takes it. D3 only: page-component `properties` is not parsed on the
+// metadata load path, so a stored page is never refused at load (its next save
+// meets the component-props gate at the metadata save door); a misspelled
+// member has no rewrite that says which of the three the author meant; and the
+// authored census found no authored value to respell — the one refused value is
+// objectui's own compile-time refusal probe.
 export const entry: SemanticMigration = {
   id: 'ui-object-gantt-markers-typed',
   surface: 'page `object-gantt` components — `properties.markers` (whose entries used to accept any value)',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-columns-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-columns-typed.ts
index bb288999ace..7a059230a3e 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-columns-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-columns-typed.ts
@@ -5,17 +5,18 @@ import type { SemanticMigration } from '../../types.js';
 // #21464 — the `object-grid` page block's `columns` was `z.array(z.unknown())`
 // although the grid reads it with one shape, so a column keyed `accessorKey` /
 // `header` / `name`, a column with no `field`, a mixed list or a key the grid
-// never reads off a column passed the component-props gate, and the grid drew no
-// column or ignored the key, in silence. Stage 2 held it because the grid's group
-// headers drew a column's `options`, which the list view's column entry does not
-// declare; objectui retired that read (the group-header labels come from the
-// object field's `options` only), so the member takes the list view's own
-// `columns` by reference — the reference it was held from. D3 only:
-// page-component `properties` is not parsed on the metadata save or load path, so
-// a stored page is never refused at load; a refused column has no rewrite that both keeps
-// what the grid draws today and honours what the author wrote; and the authored
-// census found no authored value to respell — every refused value is a fixture
-// whose refused key the grid does not draw.
+// never reads off a column passed the component-props gate, and the grid drew
+// no column or ignored the key, in silence. Stage 2 held it because the grid's
+// group headers drew a column's `options`, which the list view's column entry
+// does not declare; objectui retired that read (the group-header labels come
+// from the object field's `options` only), so the member takes the list view's
+// own `columns` by reference — the reference it was held from. D3 only:
+// page-component `properties` is not parsed on the metadata load path, so a
+// stored page is never refused at load (its next save meets the component-props
+// gate at the metadata save door); a refused column has no rewrite that both
+// keeps what the grid draws today and honours what the author wrote; and the
+// authored census found no authored value to respell — every refused value is a
+// fixture whose refused key the grid does not draw.
 export const entry: SemanticMigration = {
   id: 'ui-object-grid-columns-typed',
   surface: 'page `object-grid` components — `properties.columns` (whose entries used to accept any value)',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-export-options-closed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-export-options-closed.ts
index 9532014e6e7..da8e43ec240 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-export-options-closed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-export-options-closed.ts
@@ -2,16 +2,17 @@
 
 import type { SemanticMigration } from '../../types.js';
 
-// #21229 — an `object-grid` page block's `exportOptions` was `z.unknown()`, so a
-// bare format array (the list view's legacy spelling, which the list view lifts
-// to `{ formats }`) was accepted on the grid, whose renderer reads
+// #21229 — an `object-grid` page block's `exportOptions` was `z.unknown()`, so
+// a bare format array (the list view's legacy spelling, which the list view
+// lifts to `{ formats }`) was accepted on the grid, whose renderer reads
 // `exportOptions.formats` and lifts nothing. The row now takes the list view's
 // five-member export options OBJECT by identity, not the list view's union. D3
-// only: page-component `properties` is not parsed on the metadata save or load
-// path, so a stored page is never refused at load and there is no load-path refusal for
-// a conversion to pre-empt; the bare array never worked here, and lifting it
-// would change the export menu a deployed grid shows today; the authored census
-// found nothing to respell.
+// only: page-component `properties` is not parsed on the metadata load path, so
+// a stored page is never refused at load (its next save meets the
+// component-props gate at the metadata save door) and there is no load-path
+// refusal for a conversion to pre-empt; the bare array never worked here, and
+// lifting it would change the export menu a deployed grid shows today; the
+// authored census found nothing to respell.
 export const entry: SemanticMigration = {
   id: 'ui-object-grid-export-options-closed',
   surface: 'page `object-grid` components — `properties.exportOptions` (which used to accept any value)',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-kanban-calendar-list-members-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-kanban-calendar-list-members-typed.ts
index 0881dc7697f..c53c6230497 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-kanban-calendar-list-members-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-kanban-calendar-list-members-typed.ts
@@ -9,12 +9,12 @@ import type { SemanticMigration } from '../../types.js';
 // in silence. The rows now take the list view's own members by reference where
 // a list view declares one, and the measured shape otherwise. The grid's
 // `columns` is held at `z.unknown()`: the grid draws a column's `options`,
-// which the list view's column entry does not declare. D3 only:
-// page-component `properties` is not parsed on the metadata save or load path,
-// so a stored page is never refused at load; an off-shape value has no rewrite that
-// says what the author meant; and the authored census found no authored value
-// to respell — the refused values are fixtures probing that the renderer drops
-// them.
+// which the list view's column entry does not declare. D3 only: page-component
+// `properties` is not parsed on the metadata load path, so a stored page is
+// never refused at load (its next save meets the component-props gate at the
+// metadata save door); an off-shape value has no rewrite that says what the
+// author meant; and the authored census found no authored value to respell —
+// the refused values are fixtures probing that the renderer drops them.
 export const entry: SemanticMigration = {
   id: 'ui-object-grid-kanban-calendar-list-members-typed',
   surface: 'page `object-grid` components — `properties.fields`, `.selection`, `.selectable`, '
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-row-members-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-row-members-typed.ts
index 2408594dba9..11253c37e38 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-row-members-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-grid-row-members-typed.ts
@@ -7,7 +7,8 @@ import type { SemanticMigration } from '../../types.js';
 // with a fixed shape, so an off-shape value passed every door and the grid
 // substituted a default or dropped it in silence. The row now takes the shape
 // each read point takes. D3 only: page-component `properties` is not parsed on
-// the metadata save or load path, so a stored page is never refused at load and there is
+// the metadata load path, so a stored page is never refused at load (its next
+// save meets the component-props gate at the metadata save door) and there is
 // no load-path refusal for a conversion to pre-empt; an off-shape value has no
 // rewrite that says what the author meant; and the authored census found
 // nothing in either repository's corpora to respell.
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-kanban-conditional-formatting-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-kanban-conditional-formatting-typed.ts
index def3eb0785c..d03c49d6e4b 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-kanban-conditional-formatting-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-kanban-conditional-formatting-typed.ts
@@ -7,9 +7,10 @@ import type { SemanticMigration } from '../../types.js';
 // the list view's member refuses. objectstack-ai/objectui#11522 retired that
 // dialect from objectui's authoring faces, so the row now takes the list view's
 // own member, by reference, as `object-grid` does. D3 only: page-component
-// `properties` is not parsed on the metadata save or load path, so a stored page
-// is never refused at load; and the authored census found no working rule to respell —
-// the refused values are objectui's own refusal probes and one no-predicate
+// `properties` is not parsed on the metadata load path, so a stored page is
+// never refused at load (its next save meets the component-props gate at the
+// metadata save door); and the authored census found no working rule to respell
+// — the refused values are objectui's own refusal probes and one no-predicate
 // fixture in this package, respelled in the same change.
 export const entry: SemanticMigration = {
   id: 'ui-object-kanban-conditional-formatting-typed',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-map-gantt-tree-navigation-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-map-gantt-tree-navigation-typed.ts
index d0a694e6b28..559bda03679 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-map-gantt-tree-navigation-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-map-gantt-tree-navigation-typed.ts
@@ -9,8 +9,9 @@ import type { SemanticMigration } from '../../types.js';
 // the record page in silence. The three rows now take that schema by reference,
 // the carrier `object-grid`, `object-kanban`, `object-calendar` and
 // `object-timeline` already take. D3 only: page-component `properties` is not
-// parsed on the metadata save or load path, so a stored page is never refused at load;
-// an off-shape value has no rewrite that says what the author meant; and the
+// parsed on the metadata load path, so a stored page is never refused at load
+// (its next save meets the component-props gate at the metadata save door); an
+// off-shape value has no rewrite that says what the author meant; and the
 // authored census found nothing in either repository's corpora to respell.
 export const entry: SemanticMigration = {
   id: 'ui-object-map-gantt-tree-navigation-typed',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-master-detail-form-details-closed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-master-detail-form-details-closed.ts
index 1d7690f71cf..1e6de445c86 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-master-detail-form-details-closed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-master-detail-form-details-closed.ts
@@ -7,9 +7,10 @@ import type { SemanticMigration } from '../../types.js';
 // while the other two carriers — a relationship field's `inlineColumns` and a
 // form view's `subforms[].columns` (#20901) — were the strict
 // `InlineGridColumnSchema`; the entry is now a strict shape of the twelve keys
-// objectui's `MasterDetailForm` reads, and its `columns` REFERENCES that schema.
-// D3 only: page-component `properties` is not parsed on the metadata save or
-// load path, so a stored page is never refused at load and there is no load-path
+// objectui's `MasterDetailForm` reads, and its `columns` REFERENCES that
+// schema. D3 only: page-component `properties` is not parsed on the metadata
+// load path, so a stored page is never refused at load (its next save meets the
+// component-props gate at the metadata save door) and there is no load-path
 // refusal for a conversion to pre-empt; the authored census found no `field`
 // spelling to respell. `defineStack`'s identity-only check reaches this carrier
 // too, the reach `inline-grid-column-identity-only-currency-scale-refused`
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-aggregate-trend-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-aggregate-trend-typed.ts
index 77cdaf21ac6..edb9a661c96 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-aggregate-trend-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-aggregate-trend-typed.ts
@@ -5,18 +5,20 @@ import type { SemanticMigration } from '../../types.js';
 // #21464 — two members of the `object-metric` page block were `z.unknown()`
 // although the tile reads each with a fixed shape, so an off-shape value passed
 // the component-props gate and the tile asked the server for a measure it could
-// not answer or drew an empty badge, in silence. `aggregate` now takes the query
-// AST's aggregation functions and the chart aggregate's `groupBy` union by
-// reference (`groupBy` optional: a metric is one number), and `trend` the
-// badge's measured shape. `drillDown` and `compareTo` are held at `z.unknown()`: each
-// by-reference candidate disagrees with the tile's read (the chart's drill-down
-// declares `filter`, which the tile never reads, and refuses `report`, which it
-// draws; the dashboard widget's comparison declares `dimension`, never read on
-// this path), so each waits on a ruling. D3 only: page-component `properties`
-// is not parsed on the metadata save or load path, so a stored page is never
-// refused at load; an off-shape value has no rewrite that says what the author meant;
-// and the authored census found no authored value to respell — every refused
-// value is a fixture probing that the tile does not draw it.
+// not answer or drew an empty badge, in silence. `aggregate` now takes the
+// query AST's aggregation functions and the chart aggregate's `groupBy` union
+// by reference (`groupBy` optional: a metric is one number), and `trend` the
+// badge's measured shape. `drillDown` and `compareTo` are held at
+// `z.unknown()`: each by-reference candidate disagrees with the tile's read
+// (the chart's drill-down declares `filter`, which the tile never reads, and
+// refuses `report`, which it draws; the dashboard widget's comparison declares
+// `dimension`, never read on this path), so each waits on a ruling. D3 only:
+// page-component `properties` is not parsed on the metadata load path, so a
+// stored page is never refused at load (its next save meets the component-props
+// gate at the metadata save door); an off-shape value has no rewrite that says
+// what the author meant; and the authored census found no authored value to
+// respell — every refused value is a fixture probing that the tile does not
+// draw it.
 export const entry: SemanticMigration = {
   id: 'ui-object-metric-aggregate-trend-typed',
   surface: 'page `object-metric` components — `properties.aggregate` and `.trend` (which used to accept any '
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-compare-to-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-compare-to-typed.ts
index 47eeb7fa1a9..9d0f108a466 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-compare-to-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-compare-to-typed.ts
@@ -6,13 +6,14 @@ import type { SemanticMigration } from '../../types.js';
 // although the tile reads it with one shape, so a bare kind string, a kind
 // outside the two or a `dimension` passed the component-props gate, and the
 // tile compared against the previous period, or shifted its own filter's window
-// rather than the dimension named, in silence. It now takes the tile's read:
-// `{ kind }`, with `kind` the dashboard widget comparison's own vocabulary by
+// rather than the dimension named, in silence. It now takes the tile's read: `{
+// kind }`, with `kind` the dashboard widget comparison's own vocabulary by
 // reference, and `dimension` refused by name with a prescription (the inline
 // tile shifts the date macros in its own `filter` and never reads a dataset
 // time dimension). D3 only: page-component `properties` is not parsed on the
-// metadata save or load path, so a stored page is never refused at load; a `dimension`
-// has no rewrite that keeps the window the author meant; and the authored census
+// metadata load path, so a stored page is never refused at load (its next save
+// meets the component-props gate at the metadata save door); a `dimension` has
+// no rewrite that keeps the window the author meant; and the authored census
 // found no authored value to respell — the one refused value is a fixture
 // probing that the tile does not read `dimension`.
 export const entry: SemanticMigration = {
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-report-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-report-typed.ts
index 94b04c57727..d3f5889f554 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-report-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-report-typed.ts
@@ -2,16 +2,17 @@
 
 import type { SemanticMigration } from '../../types.js';
 
-// #21464 — the `object-metric` page block's `drillDown.report` was `z.unknown()`:
-// the tile hands it to the shared drill drawer, which draws a dataset-bound
-// report and lists the records for any other value, and no spec drill shape
-// declared it. The maintainer ruled on #21704 (fork 1, letter B) that it is
-// `ReportSchema` by reference, once a joined report refuses a block that binds
-// no dataset (#21702), so a report the member admits is one the drawer draws.
-// D3 only: page-component `properties` is not parsed on the metadata save or
-// load path, so a stored page is never refused at load; and the authored census found
-// no drawn report to respell — the refused values are objectui's probes of the
-// values the drawer does NOT draw.
+// #21464 — the `object-metric` page block's `drillDown.report` was
+// `z.unknown()`: the tile hands it to the shared drill drawer, which draws a
+// dataset-bound report and lists the records for any other value, and no spec
+// drill shape declared it. The maintainer ruled on #21704 (fork 1, letter B)
+// that it is `ReportSchema` by reference, once a joined report refuses a block
+// that binds no dataset (#21702), so a report the member admits is one the
+// drawer draws. D3 only: page-component `properties` is not parsed on the
+// metadata load path, so a stored page is never refused at load (its next save
+// meets the component-props gate at the metadata save door); and the authored
+// census found no drawn report to respell — the refused values are objectui's
+// probes of the values the drawer does NOT draw.
 export const entry: SemanticMigration = {
   id: 'ui-object-metric-drill-down-report-typed',
   surface: 'page `object-metric` components — `properties.drillDown.report` (which used to accept any value)',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-typed.ts
index 3c6c608b327..534e6164fa8 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-metric-drill-down-typed.ts
@@ -6,16 +6,18 @@ import type { SemanticMigration } from '../../types.js';
 // although the tile reads it with one shape, so a drill `filter`, a `mode`, a
 // misspelled member or a non-numeric page size passed the component-props gate
 // and the tile ignored each, in silence. It now takes the tile's read: the five
-// list members (`enabled`, `title`, `target`, `columns`, `maxRows`) are the chart
-// drill-down's own by reference, and `filter` and `mode` are refused by name with
-// the prescriptions the renderer's own type for this block carries (a metric has
-// no click event for a drill filter to resolve against, and no row for `mode` to
-// open). The drill `report` is held open, not typed: the tile draws a
-// dataset-bound report, but the spec declares no drill report yet. D3 only:
-// page-component `properties` is not parsed on the metadata save or load path, so
-// a stored page is never refused at load; a drill `filter` has no rewrite that keeps the
-// scope the author meant; and the authored census found no authored value to
-// respell — the two refused values are fixtures probing the refusal.
+// list members (`enabled`, `title`, `target`, `columns`, `maxRows`) are the
+// chart drill-down's own by reference, and `filter` and `mode` are refused by
+// name with the prescriptions the renderer's own type for this block carries (a
+// metric has no click event for a drill filter to resolve against, and no row
+// for `mode` to open). The drill `report` is held open, not typed: the tile
+// draws a dataset-bound report, but the spec declares no drill report yet. D3
+// only: page-component `properties` is not parsed on the metadata load path, so
+// a stored page is never refused at load (its next save meets the
+// component-props gate at the metadata save door); a drill `filter` has no
+// rewrite that keeps the scope the author meant; and the authored census found
+// no authored value to respell — the two refused values are fixtures probing
+// the refusal.
 export const entry: SemanticMigration = {
   id: 'ui-object-metric-drill-down-typed',
   surface: 'page `object-metric` components — `properties.drillDown` (which used to accept any value)',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-items-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-items-typed.ts
index 53d3ba9cf02..e805d311924 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-items-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-items-typed.ts
@@ -2,17 +2,18 @@
 
 import type { SemanticMigration } from '../../types.js';
 
-// #21464 — the `object-timeline` page block's `items` was `z.array(z.unknown())`:
-// each entry is objectui's authored timeline element (`TimelineFeedItem` /
-// `TimelineGanttItem`, ruled on objectui#6356), which the spec did not declare,
-// and the arm an entry must be is chosen by the row's `variant`. The maintainer
-// ruled on #21704 (fork 4, letter B): both arms closed, a feed entry's `content`
-// opaque, a row refinement pairing each entry with the arm `variant` selects,
-// and a gantt bar's dates a string or a number. D3 only: page-component
-// `properties` is not parsed on the metadata save or load path, so a stored page
-// is never refused at load; and the authored census found no drawn entry to respell —
-// the refused values are objectui's probes of its render-time gantt date
-// diagnostic.
+// #21464 — the `object-timeline` page block's `items` was
+// `z.array(z.unknown())`: each entry is objectui's authored timeline element
+// (`TimelineFeedItem` / `TimelineGanttItem`, ruled on objectui#6356), which the
+// spec did not declare, and the arm an entry must be is chosen by the row's
+// `variant`. The maintainer ruled on #21704 (fork 4, letter B): both arms
+// closed, a feed entry's `content` opaque, a row refinement pairing each entry
+// with the arm `variant` selects, and a gantt bar's dates a string or a number.
+// D3 only: page-component `properties` is not parsed on the metadata load path,
+// so a stored page is never refused at load (its next save meets the
+// component-props gate at the metadata save door); and the authored census
+// found no drawn entry to respell — the refused values are objectui's probes of
+// its render-time gantt date diagnostic.
 export const entry: SemanticMigration = {
   id: 'ui-object-timeline-items-typed',
   surface: 'page `object-timeline` components — `properties.items` (whose entries used to accept any value)',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-mapping-typed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-mapping-typed.ts
index 3a1ba81bce7..b3eedc524f2 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-mapping-typed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-object-timeline-mapping-typed.ts
@@ -8,9 +8,10 @@ import type { SemanticMigration } from '../../types.js';
 // component-props gate, and the rail bound nothing for it and drew the default
 // field. The spec now declares objectui's own declaration of the binding
 // record, four optional field names, and the row takes it. D3 only: page-
-// component `properties` is not parsed on the metadata save or load path, so a
-// stored page is never refused; and the authored census found no refused
-// authored value — every one parses.
+// component `properties` is not parsed on the metadata load path, so a stored
+// page is never refused at load (its next save meets the component-props gate
+// at the metadata save door); and the authored census found no refused authored
+// value — every one parses.
 export const entry: SemanticMigration = {
   id: 'ui-object-timeline-mapping-typed',
   surface: 'page `object-timeline` components — `properties.mapping` (which used to accept any value)',
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-page-action-row-operation-declared.ts b/packages/spec/src/migrations/entries/semantic/18.ui-page-action-row-operation-declared.ts
index a4213034b01..a35aaa8df29 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-page-action-row-operation-declared.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-page-action-row-operation-declared.ts
@@ -20,9 +20,11 @@ export const entry: SemanticMigration = {
     + 'beside `operation: \'update\'`: a row with an `api` or `script` executor, the write and a hop parsed, while '
     + 'the same action was refused. The rows now declare `ActionSchema`\'s own `operation` enum and refuse the '
     + 'pairing with the action\'s own text: the hop would follow the write, which runs no handler and no executor, '
-    + 'so its success carries no result `${result.*}` could read. A page\'s `properties` is not parsed on the '
-    + 'metadata save or load path; `os validate`\'s props gate parses it against these same rows and reports the '
-    + 'refusal at the row\'s `operation` or `onSuccess`. Measured producers: none in this repository; none in '
+    + 'so its success carries no result `${result.*}` could read. The component-props gate parses a page\'s '
+    + '`properties` against these same rows and reports the refusal at the row\'s `operation` or `onSuccess` on '
+    + '`os validate`, `os build` and `os lint`. A stored page still loads, because a page component\'s '
+    + '`properties` is not parsed on the metadata load path, and the next save of the page meets the '
+    + 'component-props gate at the metadata save door. Measured producers: none in this repository; none in '
     + 'objectui\'s action rows at its pin or main.',
   acceptanceCriteria:
     'Every page action row\'s `operation` is absent or `\'update\'`, and no row with `operation: \'update\'` carries '
diff --git a/packages/spec/src/migrations/entries/semantic/18.ui-record-line-items-props-closed.ts b/packages/spec/src/migrations/entries/semantic/18.ui-record-line-items-props-closed.ts
index 2290f99977e..0b2840e0736 100644
--- a/packages/spec/src/migrations/entries/semantic/18.ui-record-line-items-props-closed.ts
+++ b/packages/spec/src/migrations/entries/semantic/18.ui-record-line-items-props-closed.ts
@@ -3,14 +3,15 @@
 import type { SemanticMigration } from '../../types.js';
 
 // #21142 — the fourth carrier of the inline grid column, and the last
-// registered `record:*` renderer without a `ComponentPropsMap` row. The type sat
-// on the string-arm registration ledger instead, so the component-props gate
-// skipped its props bag: the showcase project page keyed all five of its
+// registered `record:*` renderer without a `ComponentPropsMap` row. The type
+// sat on the string-arm registration ledger instead, so the component-props
+// gate skipped its props bag: the showcase project page keyed all five of its
 // columns `field` and published green over a grid of empty cells. The row
 // declares the fifteen keys objectui's `LineItemsPanel` reads, and its
 // `columns` REFERENCES `InlineGridColumnSchema`. D3 only: page-component
-// `properties` is not parsed on the metadata save or load path, so a stored
-// page is never refused at load and there is no load-path refusal for a conversion to
+// `properties` is not parsed on the metadata load path, so a stored page is
+// never refused at load (its next save meets the component-props gate at the
+// metadata save door) and there is no load-path refusal for a conversion to
 // pre-empt; the one `field`-keyed producer the census found is respelled in the
 // same change.
 export const entry: SemanticMigration = {
diff --git a/packages/spec/src/ui/component.zod.ts b/packages/spec/src/ui/component.zod.ts
index edb65654b25..13b3193afc2 100644
--- a/packages/spec/src/ui/component.zod.ts
+++ b/packages/spec/src/ui/component.zod.ts
@@ -5225,10 +5225,11 @@ export const ObjectGridPropsSchema = lazySchema(() => strictObject({
    * own retirement text) and a key the block does not declare.
    *
    * No conversion lifts the array: it never worked on this surface. Read by the
-   * component-props gate (refused as an error); a stored page still saves and
-   * loads, because page-component `properties` is not parsed on the metadata
-   * save or load path (the `ui-object-grid-export-options-closed` semantic
-   * entry).
+   * component-props gate (refused as an error) on `os validate`, `os build`
+   * and `os lint` and at the metadata save door. A stored page still loads,
+   * because page-component `properties` is not parsed on the metadata load
+   * path, and its next save meets the component-props gate at the save door
+   * (the `ui-object-grid-export-options-closed` semantic entry).
    */
   exportOptions: ListViewExportOptionsSchema.optional()
     .describe("Export config — the object `{ formats?, maxRecords?, includeHeaders?, fileNamePrefix?, streaming? }`, the same block a list view's `exportOptions` declares, with `formats` drawn from `csv`, `xlsx` and `json`. A bare format array is refused: the grid reads `exportOptions.formats`, so write `{ formats: ['csv', 'xlsx'] }`"),