diff --git a/test/helpers/carve-guards.ts b/test/helpers/carve-guards.ts
index a56ef9a07..e0ce5ec25 100644
--- a/test/helpers/carve-guards.ts
+++ b/test/helpers/carve-guards.ts
@@ -87,6 +87,12 @@ export interface CarveGuard {
   minUnionBytes: number;
   /** Parity: content phrases the union must preserve. */
   mustContain: string[];
+  /**
+   * Parity: optional per-skill override for the union size-growth ceiling vs the
+   * v1.53.0.0 baseline (default 1.05). Bumped only when a deliberate cross-cutting
+   * preamble feature legitimately grows a smaller carved skeleton past 5%.
+   */
+  maxSizeRatio?: number;
 }
 
 export const CARVE_GUARDS: Record<string, CarveGuard> = {
@@ -216,6 +222,11 @@ export const CARVE_GUARDS: Record<string, CarveGuard> = {
     maxSkeletonBytes: 50_000,
     minUnionBytes: 55_000,
     mustContain: ['CHANGELOG', 'Diataxis', 'coverage'],
+    // The AUQ-failure prose fallback (v1.57.2.0) adds ~2KB to every skill's
+    // always-loaded preamble; on this small carved skeleton that lands at ~5.9%
+    // over the pre-carve/pre-AUQ v1.53.0.0 baseline. Headroom for the
+    // cross-cutting addition; all other skills keep the strict 1.05 ceiling.
+    maxSizeRatio: 1.08,
   },
   'design-consultation': {
     skill: 'design-consultation',
diff --git a/test/helpers/parity-harness.ts b/test/helpers/parity-harness.ts
index 9d43a8142..186f4833d 100644
--- a/test/helpers/parity-harness.ts
+++ b/test/helpers/parity-harness.ts
@@ -252,7 +252,7 @@ const CARVED_INVARIANTS: ParityInvariant[] = Object.values(CARVE_GUARDS).map((g)
   minBytes: g.minUnionBytes,
   mustContain: g.mustContain,
   mustHaveHeadings: ['## Preamble', '## When to invoke'],
-  maxSizeRatio: 1.05,
+  maxSizeRatio: g.maxSizeRatio ?? 1.05,
 }));
 
 export const PARITY_INVARIANTS: ParityInvariant[] = [