diff --git a/src/AcDream.App/Rendering/Wb/EntityClassificationCache.cs b/src/AcDream.App/Rendering/Wb/EntityClassificationCache.cs
index 0afaf98..f50d298 100644
--- a/src/AcDream.App/Rendering/Wb/EntityClassificationCache.cs
+++ b/src/AcDream.App/Rendering/Wb/EntityClassificationCache.cs
@@ -113,8 +113,12 @@ internal sealed class EntityClassificationCache
     /// </para>
     ///
     /// <para>
-    /// Zero cost in Release. In DEBUG, called once per static-entity cache
-    /// hit per frame — adds modest overhead. Acceptable for dev runs.
+    /// As of Phase 4 (commit f16604b) this method is exercised by unit tests
+    /// only; the dispatcher's cache-hit branch fires a simpler predicate assert
+    /// (<c>!isAnimated</c>) at production hit time. Wiring the full live-state
+    /// cross-check into the per-entity branch is the spec section 6.5 stretch
+    /// goal and remains open as a follow-up. Zero cost in Release; the method
+    /// stays here so the regression-class guard is locked behind tests.
     /// </para>
     /// </summary>
     public void DebugCrossCheck(uint entityId, IReadOnlyList<CachedBatch> liveBatches)