Don't change default, use options.

Author: JimBobSquarePants

src/ImageSharp.Web/Caching/PhysicalFileSystemCache.cs

@@ -67,7 +67,7 @@ internal static string GetCacheRoot(PhysicalFileSystemCacheOptions cacheOptions,
             string cacheRootPath = cacheOptions.CacheRootPath ?? webRootPath;
             if (string.IsNullOrEmpty(cacheRootPath))
             {
-                throw new InvalidOperationException("The cache root path can't be determined, make sure it's explicitly configured or the webroot is set.");
+                throw new InvalidOperationException("The cache root path cannot be determined, make sure it's explicitly configured or the webroot is set.");
             }
 
             if (!Path.IsPathFullyQualified(cacheRootPath))

src/ImageSharp.Web/Providers/PhysicalFileSystemProvider.cs

@@ -29,11 +29,7 @@ public PhysicalFileSystemProvider(
 #endif
             FormatUtilities formatUtilities)
             : base(GetProvider(options?.Value, environment), formatUtilities)
-        {
-        }
-
-        /// <inheritdoc/>
-        public override ProcessingBehavior ProcessingBehavior { get; protected set; } = ProcessingBehavior.All;
+            => this.ProcessingBehavior = options.Value.ProcessingBehavior;
 
         /// <summary>
         /// Determine the provider root path
@@ -47,7 +43,7 @@ internal static string GetProviderRoot(PhysicalFileSystemProviderOptions options
             string providerRootPath = options.ProviderRootPath ?? webRootPath;
             if (string.IsNullOrEmpty(providerRootPath))
             {
-                throw new InvalidOperationException("The provider root path can't be determined, make sure it's explicitly configured or the webroot is set.");
+                throw new InvalidOperationException("The provider root path cannot be determined, make sure it's explicitly configured or the webroot is set.");
             }
 
             if (!Path.IsPathFullyQualified(providerRootPath))

src/ImageSharp.Web/Providers/PhysicalFileSystemProviderOptions.cs

@@ -21,5 +21,10 @@ public class PhysicalFileSystemProviderOptions
         /// </para>
         /// </summary>
         public string ProviderRootPath { get; set; }
+
+        /// <summary>
+        /// Gets or sets the processing behavior. Defaults to <see cref="ProcessingBehavior.CommandOnly"/>.
+        /// </summary>
+        public ProcessingBehavior ProcessingBehavior { get; set; } = ProcessingBehavior.CommandOnly;
     }
 }