diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 7a9c08e..678cdf3 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -26,7 +26,7 @@ jobs:
           - { ruby: '4.0', mongoid: '9', mongodb: '8.0', bundler: default }
     env:
       MONGOID_VERSION: ${{ matrix.mongoid }}
-      COVERAGE: ${{ matrix.ruby == '4.0' && 'true' || 'false' }}
+      COVERAGE: ${{ (matrix.mongoid == '~> 3.1.0' || matrix.ruby == '4.0') && 'true' || 'false' }}
     services:
       mongodb:
         image: mongo:${{ matrix.mongodb }}
@@ -43,12 +43,24 @@ jobs:
           bundler-cache: true
       - run: bundle exec rake spec
       - name: Report coverage to Coveralls
-        if: matrix.ruby == '4.0'
+        if: matrix.mongoid == '~> 3.1.0' || matrix.ruby == '4.0'
         uses: coverallsapp/github-action@v2
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           file: coverage/.resultset.json
           format: simplecov
+          parallel: true
+          flag-name: ruby-${{ matrix.ruby }}
+
+  coverage:
+    needs: test
+    if: ${{ always() && needs.test.result == 'success' }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: coverallsapp/github-action@v2
+        with:
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          parallel-finished: true
 
   lint:
     runs-on: ubuntu-22.04
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f3dde02..88c6af3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ### 0.9.0 (Next)
 
+* [#68](https://github.com/mongoid/mongoid_fulltext/pull/68): Cover candidate-budget boundaries and standalone version loading, and combine coverage from actual legacy and modern drivers - [@dblock](https://github.com/dblock).
 * [#61](https://github.com/mongoid/mongoid_fulltext/pull/61): Support weighted fields with configurable maximum or summed field-score aggregation - [@dblock](https://github.com/dblock).
 * [#60](https://github.com/mongoid/mongoid_fulltext/pull/60): Extract ngram calculation and index-definition planning for maintainability without changing model APIs or search behavior - [@tomasc](https://github.com/tomasc), [@dblock](https://github.com/dblock).
 * [#59](https://github.com/mongoid/mongoid_fulltext/pull/59): Document and cover class-level indexing timeout options - [@dblock](https://github.com/dblock).
diff --git a/Gemfile b/Gemfile
index 48006aa..7983b31 100644
--- a/Gemfile
+++ b/Gemfile
@@ -14,7 +14,7 @@ group :test do
     gem 'database_cleaner', '~> 1.8'
   end
   gem 'rspec'
-  gem 'simplecov', '~> 0.22', require: false if ENV['COVERAGE'] == 'true'
+  gem 'simplecov', RUBY_VERSION < '2.5' ? '~> 0.16.0' : '~> 0.22', require: false if ENV['COVERAGE'] == 'true'
 end
 
 group :development do
diff --git a/spec/mongoid/candidate_limits_spec.rb b/spec/mongoid/candidate_limits_spec.rb
new file mode 100644
index 0000000..b0f1215
--- /dev/null
+++ b/spec/mongoid/candidate_limits_spec.rb
@@ -0,0 +1,19 @@
+require 'spec_helper'
+
+describe 'Full-text candidate limits' do
+  it 'bounds initial candidates and continues with limited candidates for later ngrams' do
+    config = BasicArtwork.mongoid_fulltext_config.values.first
+    original = config[:max_candidate_set_size]
+    begin
+      config[:max_candidate_set_size] = 1
+      artworks = 2.times.map { BasicArtwork.create!(title: 'alphabet beta') }
+
+      results = BasicArtwork.fulltext_search('alphabet beta', max_results: 1, return_scores: true)
+      expect(results.length).to eq(1)
+      expect(artworks).to include(results.first.first)
+      expect(results.first.last).to be > 0
+    ensure
+      config[:max_candidate_set_size] = original
+    end
+  end
+end
diff --git a/spec/version_spec.rb b/spec/version_spec.rb
new file mode 100644
index 0000000..a750f27
--- /dev/null
+++ b/spec/version_spec.rb
@@ -0,0 +1,9 @@
+require 'spec_helper'
+
+describe Mongoid::FullTextSearch do
+  it 'loads a standalone semantic version' do
+    stub_const('Mongoid::FullTextSearch', Module.new)
+    load File.expand_path('../lib/mongoid/full_text_search/version.rb', __dir__)
+    expect(Mongoid::FullTextSearch::VERSION).to match(/\A\d+\.\d+\.\d+\z/)
+  end
+end