diff --git a/.changeset/29397-overlay-pair-fix-one-predicate.md b/.changeset/29397-overlay-pair-fix-one-predicate.md
new file mode 100644
index 00000000000..be6b3182a46
--- /dev/null
+++ b/.changeset/29397-overlay-pair-fix-one-predicate.md
@@ -0,0 +1,10 @@
+---
+'@objectstack/metadata-protocol': patch
+---
+
+refactor(metadata-protocol): the two overlay-write closes ask one "the fix can be taken" predicate
+
+Clause-②: no
+Metadata-protocol: none
+
+The close of a write naming the read-only base itself and the close of the package-less write each judged, step for step, whether the fix their refusal names can be taken: the base has a pair id, the ensure door would answer or create the pair, the base records a version, and the override write gate admits the declared body into the pair. Those four steps now live once (`overlayPairFixOf` and `overlayPairFixAdmits`, internal to the package), and each close keeps only its own difference: the named close reads no row and accepts the named package among several shippers; the package-less close requires exactly one shipper and classifies the stored row. No refusal, status, code or sentence changes, and no write that was open or closed before changes side.
diff --git a/packages/metadata-protocol/src/protocol-packaged-base-refusal.ts b/packages/metadata-protocol/src/protocol-packaged-base-refusal.ts
index 410bf525f92..5956fab0741 100644
--- a/packages/metadata-protocol/src/protocol-packaged-base-refusal.ts
+++ b/packages/metadata-protocol/src/protocol-packaged-base-refusal.ts
@@ -339,6 +339,82 @@ export function namedBaseOverlayWriteRefusal(
     return closedOverlayWriteError(message);
 }
 
+// ─────────────────────────────────────────────────────────────────────────
+// ADR-0146 D1, D11 — "the fix the close names can be taken": one predicate
+// ─────────────────────────────────────────────────────────────────────────
+
+/** The pair an overlay-write close sends the write into, and the `basedOn` its declaration records. */
+export interface OverlayPairFix {
+    readonly base: string;
+    readonly pair: string;
+    readonly basedOn: string;
+}
+
+/**
+ * [ADR-0146 D1, D11] The registry half of whether the fix both overlay-write
+ * closes name — write it into `base`'s pair, declaring the override — can be
+ * taken, or `null` when it cannot: read from the steps that write takes.
+ *
+ *  - the base has a pair id (`customizationPackageId`; an id ending in
+ *    `.custom` has none);
+ *  - the ensure door would answer or create the pair
+ *    ({@link customizationPairEnsureRefusal});
+ *  - the base records a version (`basedOn`, its `manifest.version`, the value
+ *    the ceremony records too).
+ *
+ * The other half is {@link overlayPairFixAdmits}, the override write gate on
+ * the declared body. Two halves of one predicate so that a close may read its
+ * own subject between them — the package-less close reads the item's stored
+ * rows only for a name the registry has not already left open — and ⛔ each
+ * close keeps only its own difference: which base it judges, and which body.
+ * {@link namedBaseCloseSubject} and `packagelessCloseSubject`
+ * (`protocol-packageless-overlay-migration.ts`) ask both. Registry reads only.
+ */
+export function overlayPairFixOf(
+    host: { readonly engine: ObjectStackProtocolImplementation['engine'] },
+    base: string,
+): OverlayPairFix | null {
+    const pairId = customizationPackageId(base);
+    if (!pairId.ok) return null; // no pair to name (the census's `no_pair`)
+    const pair = pairId.value;
+    const registry = (host.engine as { registry?: PairRegistry } | undefined)?.registry;
+    if (!registry || typeof registry.getPackage !== 'function') return null;
+    if (customizationPairEnsureRefusal(host.engine, registry, base, pair) !== undefined) return null; // the ensure door would refuse
+    const basedOn = registry.getPackage(base)?.manifest?.version;
+    if (typeof basedOn !== 'string' || basedOn === '') return null; // no `basedOn` to declare
+    return { base, pair, basedOn };
+}
+
+/**
+ * [ADR-0146 D1, D2, D11] The gate half of {@link overlayPairFixOf}: whether
+ * the override write gate admits the body the fix writes into the pair — the
+ * close's `body` (a save's, or the stored row's), else the item's bare
+ * identity at `member`, declaring `overrides: { package: base, basedOn }`. An
+ * `email_template` member at a locale the base does not ship is refused
+ * there, so its write stays open.
+ */
+export function overlayPairFixAdmits(
+    host: { readonly overrideWriteVerdict: (request: OverrideWriteSubject) => OverrideWriteVerdict },
+    fix: OverlayPairFix,
+    subject: {
+        /** The singular type. */
+        readonly type: string;
+        readonly name: string;
+        readonly body: Record<string, unknown> | undefined;
+        /** The bundle member, as `OVERLAY_MEMBER_COLUMN` holds it. */
+        readonly member: string | null | undefined;
+    },
+): boolean {
+    const { type, name, body, member } = subject;
+    const disc = member === undefined ? undefined : overlayMemberField(type);
+    const declaredBody = {
+        ...(body ?? { name, ...(disc && member !== null ? { [disc]: member } : {}) }),
+        overrides: { package: fix.base, basedOn: fix.basedOn },
+    };
+    const verdict = host.overrideWriteVerdict({ type, name, packageId: fix.pair, item: declaredBody });
+    return verdict.verdict !== 'refuse';
+}
+
 /** The class members {@link namedBaseCloseSubject} reads, typed as the class declares them. */
 export interface NamedBaseCloseHost {
     readonly engine: ObjectStackProtocolImplementation['engine'];
@@ -367,16 +443,15 @@ export interface NamedBaseWriteSubject {
  * overlay types — the package-less close's reading of "packaged"
  * (`overlayBaseShippers`, the reading `os migrate packageless-overlays`
  * classifies by), with the named package among the shippers — and where the
- * fix the refusal names can be taken, read from the steps that write takes:
+ * fix the refusal names can be taken: {@link overlayPairFixOf} and
+ * {@link overlayPairFixAdmits}, the predicate the package-less close asks too
+ * (a pair id, the ensure door, a base version, the override write gate
+ * admitting the declared body — an `email_template` member at a locale the
+ * base does not ship stays open, as the package-less one does).
  *
- *  - the base has a pair id (`customizationPackageId`);
- *  - the ensure door would answer or create the pair
- *    ({@link customizationPairEnsureRefusal});
- *  - the base records a version (`basedOn`, its `manifest.version`, the value
- *    the ceremony records too);
- *  - the override write gate admits the declared body into the pair (an
- *    `email_template` member at a locale the base does not ship is refused
- *    there, so its write stays open, as the package-less one does).
+ * This close's own difference: it reads no row (the declared body is the
+ * save's, else the item's identity), and the named package may be one of
+ * several shippers.
  *
  * A body carrying `overrides` is not judged here: the D2 gate answers a
  * declaration outside the pair, the schema gate a malformed one, as before.
@@ -398,14 +473,8 @@ export function namedBaseCloseSubject(
     // a malformed one (`422 INVALID_METADATA`).
     if (isPlainRecord(request.item) && 'overrides' in request.item) return null;
     if (!this.overlayBaseShippers(request.type, request.name).includes(base)) return null;
-    const pairId = customizationPackageId(base);
-    if (!pairId.ok) return null; // no pair to name
-    const pair = pairId.value;
-    const registry = (this.engine as { registry?: PairRegistry } | undefined)?.registry;
-    if (!registry || typeof registry.getPackage !== 'function') return null;
-    if (customizationPairEnsureRefusal(this.engine, registry, base, pair) !== undefined) return null;
-    const basedOn = registry.getPackage(base)?.manifest?.version;
-    if (typeof basedOn !== 'string' || basedOn === '') return null; // no `basedOn` to declare
+    const fix = overlayPairFixOf(this, base);
+    if (fix === null) return null;
 
     // The gate's verdict on the declared body, written into the pair.
     const type = PLURAL_TO_SINGULAR[request.type] ?? request.type;
@@ -413,14 +482,8 @@ export function namedBaseCloseSubject(
     const member = written !== undefined && request.member === undefined
         ? overlayMemberOfBody(type, written)
         : overlayMemberValue(type, request.member);
-    const disc = member === undefined ? undefined : overlayMemberField(type);
-    const declaredBody = {
-        ...(written ?? { name: request.name, ...(disc && member !== null ? { [disc]: member } : {}) }),
-        overrides: { package: base, basedOn },
-    };
-    const verdict = this.overrideWriteVerdict({ type, name: request.name, packageId: pair, item: declaredBody });
-    if (verdict.verdict === 'refuse') return null;
-    return { base, pair };
+    if (!overlayPairFixAdmits(this, fix, { type, name: request.name, body: written, member })) return null;
+    return { base, pair: fix.pair };
 }
 
 // ─────────────────────────────────────────────────────────────────────────
diff --git a/packages/metadata-protocol/src/protocol-packageless-overlay-migration.ts b/packages/metadata-protocol/src/protocol-packageless-overlay-migration.ts
index c95c95c7e6c..6cf4c7f8b28 100644
--- a/packages/metadata-protocol/src/protocol-packageless-overlay-migration.ts
+++ b/packages/metadata-protocol/src/protocol-packageless-overlay-migration.ts
@@ -131,10 +131,15 @@ import {
 } from '@objectstack/spec/kernel';
 import { PLURAL_TO_SINGULAR, SINGULAR_TO_PLURAL } from '@objectstack/spec/shared';
 import { storedRowDocument } from './item-lock.js';
-import { OVERLAY_MEMBER_COLUMN, overlayMemberField, overlayMemberOfBody, overlayMemberValue } from './migrations/overlay-index.js';
+import { OVERLAY_MEMBER_COLUMN, overlayMemberOfBody, overlayMemberValue } from './migrations/overlay-index.js';
 import type { ObjectStackProtocolImplementation } from './protocol.js';
-import { customizationPairEnsureRefusal, type PairRegistry } from './protocol-customization-package.js';
-import { overrideWriteMemberOf, type OverrideWriteSubject, type OverrideWriteVerdict } from './protocol-packaged-base-refusal.js';
+import {
+    overlayPairFixAdmits,
+    overlayPairFixOf,
+    overrideWriteMemberOf,
+    type OverrideWriteSubject,
+    type OverrideWriteVerdict,
+} from './protocol-packaged-base-refusal.js';
 import { readOnlyShippingPackages, shippingPackageIds } from './protocol-environment-rows.js';
 import { isServedOverrideRowOf } from './served-override.js';
 import { SysMetadataRepository } from './sys-metadata-repository.js';
@@ -710,14 +715,15 @@ export interface PackagelessWriteSubject {
  *    read-only package ships). `shadowed` applies to a stored row only: a
  *    first write has nothing in the pair to be shadowed by;
  *  - its move must be able to succeed, read from the steps the ceremony
- *    takes: the ensure door would ensure the pair
- *    ({@link customizationPairEnsureRefusal}), the base records a version
- *    (`basedOn`), and the override write gate admits the declared body into
- *    the pair. An `email_template` member at a locale the base does not ship
- *    is refused there (#28777) and stays open: the ceremony moves such a row
- *    as the pair's own member, declaring nothing (#28904), and the close
- *    reaches only the declared-override moves, so its package-less write is
- *    the one it had before the close.
+ *    takes: `overlayPairFixOf` and `overlayPairFixAdmits`
+ *    (`protocol-packaged-base-refusal.ts`), the predicate the close of the
+ *    write naming the base asks too — the ensure door would ensure the pair,
+ *    the base records a version (`basedOn`), and the override write gate
+ *    admits the declared body into the pair. An `email_template` member at a
+ *    locale the base does not ship is refused there (#28777) and stays open:
+ *    the ceremony moves such a row as the pair's own member, declaring
+ *    nothing (#28904), and the close reaches only the declared-override
+ *    moves, so its package-less write is the one it had before the close.
  *
  * Registry reads first; the one store read (the item's rows) only for a name
  * the registry has not already left open.
@@ -731,14 +737,9 @@ export async function packagelessCloseSubject(
     const shippers = this.overlayBaseShippers(request.type, request.name);
     if (shippers.length !== 1) return null; // environment metadata, or `multi_shipped`
     const base = shippers[0]!;
-    const pairId = customizationPackageId(base);
-    if (!pairId.ok) return null; // `no_pair`
-    const pair = pairId.value;
-    const registry = (this.engine as { registry?: PairRegistry } | undefined)?.registry;
-    if (!registry || typeof registry.getPackage !== 'function') return null;
-    if (customizationPairEnsureRefusal(this.engine, registry, base, pair) !== undefined) return null; // step 1 fails
-    const basedOn = baseVersionOf(this, base);
-    if (basedOn === undefined) return null; // no `basedOn` to record
+    // `no_pair`, a pair step 1 cannot ensure, or no `basedOn` to record.
+    const fix = overlayPairFixOf(this, base);
+    if (fix === null) return null;
 
     // The item's stored rows, both spellings, every package: the census's read.
     const spellings = [...new Set([type, SINGULAR_TO_PLURAL[type] ?? type])];
@@ -768,12 +769,6 @@ export async function packagelessCloseSubject(
     if (classified.disposition !== 'movable') return null;
 
     // Step 2's gate: the declared body, into the pair.
-    const disc = member === undefined ? undefined : overlayMemberField(type);
-    const declaredBody = {
-        ...(body ?? { name: request.name, ...(disc && member !== null ? { [disc]: member } : {}) }),
-        overrides: { package: base, basedOn },
-    };
-    const verdict = this.overrideWriteVerdict({ type, name: request.name, packageId: pair, item: declaredBody });
-    if (verdict.verdict === 'refuse') return null;
-    return { base, pair };
+    if (!overlayPairFixAdmits(this, fix, { type, name: request.name, body, member })) return null;
+    return { base, pair: fix.pair };
 }
diff --git a/packages/metadata-protocol/src/protocol.named-base-overlay-write.test.ts b/packages/metadata-protocol/src/protocol.named-base-overlay-write.test.ts
index 4a79bb8f1c1..5ea6dbf4b8e 100644
--- a/packages/metadata-protocol/src/protocol.named-base-overlay-write.test.ts
+++ b/packages/metadata-protocol/src/protocol.named-base-overlay-write.test.ts
@@ -52,12 +52,20 @@ const BASE_VERSION = '3.2.0';
 const NO_PAIR_BASE = 'com.legacy.app';
 /** A writable runtime package: no manifest booted it. */
 const WRITABLE = 'com.acme.workspace';
+/** A read-only code package whose id forms no pair: an id ending in `.custom` (ADR-0146 D3). */
+const NO_PAIR_ID_BASE = 'com.vendor.custom';
+/** A read-only code package that records no version, with its pair already installed. */
+const NO_VERSION_BASE = 'com.nover.app';
+const NO_VERSION_PAIR = 'com.nover.app.custom';
 
 const MANIFESTS: Record<string, Record<string, unknown>> = {
     [BASE]: { dependencies: {}, version: BASE_VERSION, namespace: 'acme' },
     [PAIR]: { dependencies: { [BASE]: '^3' }, version: '0.1.0', namespace: 'acme_custom' },
     [NO_PAIR_BASE]: { dependencies: {}, version: '1.0.0' },
     [WRITABLE]: { dependencies: {} },
+    [NO_PAIR_ID_BASE]: { dependencies: {}, version: '1.0.0', namespace: 'vendor' },
+    [NO_VERSION_BASE]: { dependencies: {}, namespace: 'nover' },
+    [NO_VERSION_PAIR]: { dependencies: { [NO_VERSION_BASE]: '*' }, version: '0.1.0', namespace: 'nover_custom' },
 };
 
 /** One item of each overlay type the base ships, and a body a write carries. */
@@ -78,6 +86,8 @@ const VIEW = ITEMS[0]!;
 const SHIPPED = [
     ...ITEMS.map((i) => ({ type: i.type, name: i.name, pkg: BASE })),
     { type: 'dashboard', name: 'legacy_board', pkg: NO_PAIR_BASE },
+    { type: 'dashboard', name: 'vendor_board', pkg: NO_PAIR_ID_BASE },
+    { type: 'dashboard', name: 'nover_board', pkg: NO_VERSION_BASE },
 ];
 const PACKAGED = 'Packaged';
 
@@ -109,7 +119,7 @@ function makeProtocol() {
     const packageRecord = (id: string) => (MANIFESTS[id] ? { manifest: { id, ...MANIFESTS[id] } } : undefined);
     const engine: any = {
         // A booted code package is read-only (`isWritablePackage` reads `manifests` first).
-        manifests: new Map([[BASE, {}], [NO_PAIR_BASE, {}]]),
+        manifests: new Map([[BASE, {}], [NO_PAIR_BASE, {}], [NO_PAIR_ID_BASE, {}], [NO_VERSION_BASE, {}]]),
         async find(t: string, q?: { where?: Record<string, unknown>; limit?: number }) {
             const rows = table(t).filter((r) => matches(r, q?.where));
             return typeof q?.limit === 'number' ? rows.slice(0, q.limit) : rows;
@@ -377,6 +387,52 @@ describe('CONTROLS: the writes the close leaves open, as on main', () => {
  * the commit CREATED is reverted by removing the row, which writes nothing and
  * stays open.
  */
+/**
+ * Each step of "the fix the refusal names can be taken" (the pair id, the
+ * ensure door, the base's version, the override write gate admitting the
+ * declared body) leaves the write naming the base open where it fails: the
+ * refusal would name a door the author cannot take. The ensure door's step is
+ * the CONTROL above (`a read-only base whose pair cannot be ensured`); a
+ * shipped member's closed save is the five-type case at the top.
+ */
+describe('CONTROLS: every step the fix takes, failing, leaves the write naming the base open (ADR-0146 D1, D11)', () => {
+    it('a read-only base whose id forms no pair (an id ending in `.custom`) keeps the write naming it: there is no pair to name', async () => {
+        const { protocol, rows } = makeProtocol();
+
+        const saved = await protocol.saveMetaItem({
+            type: 'dashboard', name: 'vendor_board', item: { name: 'vendor_board', label: 'Vendor', widgets: [] }, packageId: NO_PAIR_ID_BASE,
+        });
+
+        expect(saved).toMatchObject({ success: true });
+        expect(rows('dashboard', 'vendor_board')).toEqual([{ package_id: NO_PAIR_ID_BASE, state: 'active', label: 'Vendor' }]);
+    });
+
+    it('a read-only base that records no version, its pair installed, keeps the write naming it: there is no `basedOn` to declare', async () => {
+        // The ensure door answers an installed pair without reading the base's
+        // version, so this is the version step's own case.
+        const { protocol, rows } = makeProtocol();
+
+        const saved = await protocol.saveMetaItem({
+            type: 'dashboard', name: 'nover_board', item: { name: 'nover_board', label: 'Nover', widgets: [] }, packageId: NO_VERSION_BASE,
+        });
+
+        expect(saved).toMatchObject({ success: true });
+        expect(rows('dashboard', 'nover_board')).toEqual([{ package_id: NO_VERSION_BASE, state: 'active', label: 'Nover' }]);
+    });
+
+    it('an email template at a locale the base does not ship keeps the write naming the base: the override write gate refuses its declared body', async () => {
+        const { protocol, rows } = makeProtocol();
+        const email = ITEMS.find((i) => i.type === 'email_template')!;
+
+        const saved = await protocol.saveMetaItem({
+            type: email.type, name: email.name, item: { ...email.body('Bienvenue'), locale: 'fr-FR' }, packageId: BASE,
+        });
+
+        expect(saved).toMatchObject({ success: true });
+        expect(rows(email.type, email.name)).toEqual([{ package_id: BASE, state: 'active', label: 'Bienvenue' }]);
+    });
+});
+
 describe('the commit doors: restoring a row bound to the base is closed, removing one stays open (#29390)', () => {
     /** Each commit a second apart, so the package rollback's "strictly newer" reads an order. */
     let clock = Date.parse('2026-11-02T00:00:00.000Z');