diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0bd7e4870..06e2f1633 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,10 @@ All notable changes to Aver are documented here. Starting with 0.10.0, minor rel
 - **Every backend runs the same match.** The compiler turns such a match into nested ordinary matches right after checking it, so the VM, generated Rust, wasm-gc, `wasip2` and the Lean export all read the same program. A `match` that uses these patterns inside a `yield` function is refused for now; move it into a helper function.
 - **`aver format` prints match patterns in one spelling:** `[a, b, ..rest]`, `Option.Some(0)`, `(x, _)`.
 
+### Fixed — a large certificate package checks again after Vector versions
+
+- **`aver-cert check` of a large package no longer runs out of time on two acceptance proofs.** The package's proofs of the host-helper table and of the plans' layout unfolded definitions that read the decoded type section, and Lean evaluated the whole decode before it could use the package's declared type-section cut. After Vector values became versions (more types in the type section), btc-listener's package passed the 9000-second limit where it had taken minutes. The two proofs now read the type section only through the cut: 13 s and 68 s on that package. Packages must be produced again to get the new proofs.
+
 ### Fixed — `aver proof --gate` passes a law that became universal
 
 - **A law promoted from bounded to universal no longer fails the gate.** A bounded law records no axioms, and its universal proof usually depends on Lean's standard axioms, so the gate reported `REGRESSION <law>: axioms grew {} -> {Classical.choice,Quot.sound,propext}`. It now prints `promoted <law>: bounded -> universal, now uses …` and lists the law under `Promoted:` in the summary. The gate still fails when a law newly depends on any other axiom (`sorryAx`, `Lean.ofReduceBool`, a user `axiom`) at any tier, when it newly depends on one of the standard three at the same tier, and on a missing law, a lower tier or a changed backend.
diff --git a/aver-cert/src/engine/render_package.rs b/aver-cert/src/engine/render_package.rs
index 1e78ea560..dedaa6347 100644
--- a/aver-cert/src/engine/render_package.rs
+++ b/aver-cert/src/engine/render_package.rs
@@ -557,10 +557,16 @@ fn render_artifact(
                  AverCert.DeclaredLayout.Chars.carrierHelperAbsent_eq,\n    \
                  AverCert.DeclaredLayout.Chars.boxIdx_eq, AverCert.DeclaredLayout.Chars.toIndexIdx_eq,\n    \
                  AverCert.DeclaredLayout.Chars.cmpIdx_eq{cuts}]\n  \
-                 decide +kernel",
+                 {carrier}decide +kernel",
                 r.roles_lean_value(),
-                cuts = if layout {
-                    ", CertDecode.carrierState, types_cut, exports_cut"
+                cuts = if layout { ", exports_cut" } else { "" },
+                // The carrier is read through the type-section cut. Its
+                // definition is a `match` on the decoded type section, so it
+                // is unfolded by its unconditional equation with matcher
+                // reduction off: otherwise `simp` evaluates the whole type
+                // decode in the elaborator before the cut can rewrite it.
+                carrier = if layout {
+                    "simp -iota only [CertDecode.carrierState.eq_def, types_cut]\n  "
                 } else {
                     ""
                 },
@@ -651,13 +657,19 @@ fn render_artifact(
             "\n     "
         ),
     );
-    // With a declared layout the helper types are read from it.
+    // With a declared layout the helper types are read from it. The
+    // definitions that `match` on the decoded type section are unfolded by
+    // their unconditional equations with matcher reduction off, so the type
+    // section is read only through its cut, in the kernel: `simp` with the
+    // definitions themselves evaluates the whole type decode in the
+    // elaborator first (btc-listener: over 10 minutes per theorem).
     let rest_proof = if layout {
         "(AverCert.DeclaredLayout.plansAcceptedRest_of_layout layout_ok (by\n    \
          dsimp only [AverCert.DeclaredLayout.plansAcceptedRestL, data]\n    \
-         simp only [AverCert.TypeTable.typeTableConfirmed, AverCert.TypeTable.carrierConfirmed,\n      \
-         CertDecode.carrierState, AverCert.DeclaredLayout.roleTypesPinnedL,\n      \
-         AverCert.DeclaredLayout.roleTypePinnedL, AverCert.WasmSlice.typeSectionMatches, types_cut]\n    \
+         simp -iota only [AverCert.TypeTable.typeTableConfirmed.eq_def,\n      \
+         AverCert.TypeTable.carrierConfirmed.eq_def, CertDecode.carrierState.eq_def,\n      \
+         AverCert.DeclaredLayout.roleTypesPinnedL, AverCert.DeclaredLayout.roleTypePinnedL,\n      \
+         AverCert.WasmSlice.typeSectionMatches.eq_def, types_cut]\n    \
          decide +kernel))"
     } else {
         "(by decide +kernel)"