diff --git a/gitnexus/bench/emit-persistence/baselines.json b/gitnexus/bench/emit-persistence/baselines.json
index 0bb4250c3..93806b252 100644
--- a/gitnexus/bench/emit-persistence/baselines.json
+++ b/gitnexus/bench/emit-persistence/baselines.json
@@ -1,5 +1,6 @@
 {
   "fingerprint": "1b9dd0b783899b47067c36511d241860f291ac736e57682b0ece14148e3958ff",
   "scaling_budget": 1.8,
-  "_note": "fingerprint = sha256 over per-file digests (filename + sha256(file bytes)), entry list sorted — binds each emitted line to its file so a row routed to the WRONG pair file changes the hash, AND catches within-file row reordering (file bytes hashed as-written). Byte-identity gate for #2203 U2/U3. NOTE: a future change that legitimately reorders emit (without changing the node/edge SET) will trip --check; regenerate then. scaling_budget bounds (t_large/t_small)/(LARGE/SMALL): observed ~0.95-1.05 (linear); 1.8 tolerates disk-I/O timing noise on CI while still catching an O(n^2) re-regression (~4x). Regenerate via `node --import tsx bench/emit-persistence/measure.mjs`."
+  "max_ms_large": 1000,
+  "_note": "fingerprint = sha256 over per-file digests (filename + sha256(file bytes)), entry list sorted — binds each emitted line to its file so a row routed to the WRONG pair file changes the hash, AND catches within-file row reordering (file bytes hashed as-written). Byte-identity gate for #2203 U2/U3. NOTE: a future change that legitimately reorders emit (without changing the node/edge SET) will trip --check; regenerate then. scaling_budget bounds (t_large/t_small)/(LARGE/SMALL): observed ~0.95-1.05 (linear); 1.8 tolerates disk-I/O timing noise on CI while still catching an O(n^2) re-regression (~4x). max_ms_large=1000ms is a coarse absolute backstop (observed ~200ms) that catches a gross uniform slowdown the ratio gate misses; generous so CI host noise won't flake it. Regenerate via `node --import tsx bench/emit-persistence/measure.mjs`."
 }
diff --git a/gitnexus/bench/emit-persistence/measure.mjs b/gitnexus/bench/emit-persistence/measure.mjs
index 49fbe278c..f7623bc34 100644
--- a/gitnexus/bench/emit-persistence/measure.mjs
+++ b/gitnexus/bench/emit-persistence/measure.mjs
@@ -198,6 +198,15 @@ if (!CHECK) {
         `(${SMALL}->${LARGE} entities, ms ${result.elapsed_ms_small}->${result.elapsed_ms_large})`,
     );
   }
+  // Absolute backstop: the scaling ratio alone passes a uniform Nx slowdown (it
+  // only compares large/small). A generous, host-noise-tolerant ceiling catches
+  // a gross absolute regression. Opt-in (only enforced when max_ms_large is set).
+  if (base.max_ms_large !== undefined && result.elapsed_ms_large >= base.max_ms_large) {
+    failures.push(
+      `absolute wall-time regression: elapsed_ms_large ${result.elapsed_ms_large}ms >= budget ` +
+        `${base.max_ms_large}ms (coarse backstop, not a tight SLA)`,
+    );
+  }
   process.stdout.write(JSON.stringify(result) + '\n');
   if (failures.length > 0) {
     for (const f of failures) process.stderr.write(`[emit-persistence --check] FAIL: ${f}\n`);