diff --git a/.changeset/olive-pugs-sniff.md b/.changeset/olive-pugs-sniff.md
new file mode 100644
index 0000000000..bce67bc41d
--- /dev/null
+++ b/.changeset/olive-pugs-sniff.md
@@ -0,0 +1,19 @@
+---
+'@objectstack/spec': patch
+---
+
+Fix `snap.grid` on the Studio flow-builder config pointing authors at the wrong key, and gate the cause repo-wide.
+
+`strictUnknownKeyError` indexes an alias table by `aliasProbe(key)` — lowercased, with `_`, `-` and spaces stripped. Two keys in one table that normalise identically therefore share one index, and the later entry silently overwrites the earlier one. Nothing checked for that.
+
+`these snap settings` listed `grid: 'gridSize'` and, at the end of the same table, `grid_: 'showGrid'`. Writing `grid: 24` (the grid's pixel pitch) was answered with:
+
+```
+Did you mean `grid` -> `showGrid`?
+```
+
+`showGrid` is a boolean, so following that advice was rejected a second time. It now answers `grid` -> `gridSize`, and `gridSize: 24` parses. `visible` still covers the show/hide intent.
+
+Three other tables carried a second spelling of a key they already had — `rollup`/`rollUp` on a field, `object_name`/`objectName` on a webhook, `strokeDasharray`/`strokeDashArray` on a chart series. Both spellings pointed at the same target there, so the overwrite changed nothing and no author could trip on it; the redundant entries are removed. Because the probe already folds case and separators, the surviving entry accepts every spelling the deleted one did — no authoring input changes meaning.
+
+`alias-integrity.test.ts` now rejects any alias table containing two keys that share a probe, judged with the real `aliasProbe` rather than a copy of it, so this class cannot come back.
diff --git a/packages/spec/authorable-surface.base.json b/packages/spec/authorable-surface.base.json
index b5239b7db6..fcfe5cf368 100644
--- a/packages/spec/authorable-surface.base.json
+++ b/packages/spec/authorable-surface.base.json
@@ -1,6 +1,6 @@
 {
   "description": "In-tree anchor for the authorable-surface deletion gate (#4650, #5235): a verbatim copy of the keys in authorable-surface.json as they stood at `baseRev`, a commit on origin/main. A build that CAN reach origin/main anchors on the merge base instead, and re-verifies this file against `baseRev` — so a PR that edits it to hide a deletion goes red wherever the network exists. A build that CANNOT reach GitHub (image-build stages, air-gapped, fork, historical-tag reproduction) anchors here instead of failing. Written only by `gen:schema`, only from a git-resolved baseline — never from the build that is being checked. See #5235.",
-  "baseRev": "cdfbee2f08e3316d4606d21dd8e7c2403a59030b",
+  "baseRev": "168f60f1adf5e4f44ed818eccbba442052722328",
   "keys": [
     "ai/AIModelConfig:maxTokens",
     "ai/AIModelConfig:model",
@@ -2132,6 +2132,7 @@
     "automation/DecisionOutputDef:required",
     "automation/DecisionOutputDef:type",
     "automation/DeleteRecordConfig:filter",
+    "automation/DeleteRecordConfig:multi",
     "automation/DeleteRecordConfig:objectName",
     "automation/ETLDestination:config",
     "automation/ETLDestination:connector",
@@ -2418,6 +2419,7 @@
     "automation/TryCatchConfig:try",
     "automation/UpdateRecordConfig:fields",
     "automation/UpdateRecordConfig:filter",
+    "automation/UpdateRecordConfig:multi",
     "automation/UpdateRecordConfig:objectName",
     "automation/WaitExecutorConfig:conditionMaxPolls",
     "automation/WaitExecutorConfig:conditionPollIntervalMs",
diff --git a/packages/spec/src/automation/webhook.zod.ts b/packages/spec/src/automation/webhook.zod.ts
index f64df3b14d..15c08f7dc9 100644
--- a/packages/spec/src/automation/webhook.zod.ts
+++ b/packages/spec/src/automation/webhook.zod.ts
@@ -138,8 +138,9 @@ export const WebhookSchema = lazySchema(() => strictObject({
     // `active` (`mapWebhookToRow` in plugin-webhooks does the remap). An admin
     // or agent reading a row back and re-authoring it from those column names
     // is the concrete path here, and neither word is within edit distance.
+    // The column spelling alone covers `objectName` too — `aliasProbe` folds
+    // case and separators, so both spellings share one probe (#5481).
     object_name: 'object',
-    objectName: 'object',
     active: 'isActive',
     enabled: 'isActive',
     // The trigger list, named as the neighbouring surfaces name it.
diff --git a/packages/spec/src/data/field.zod.ts b/packages/spec/src/data/field.zod.ts
index ce6780e87c..2d758a55f1 100644
--- a/packages/spec/src/data/field.zod.ts
+++ b/packages/spec/src/data/field.zod.ts
@@ -397,7 +397,10 @@ export const FieldSchema = lazySchema(() => strictObject({
     relatedTo: 'reference', referenceTo: 'reference', target: 'reference', targetObject: 'reference', lookupObject: 'reference',
     onDelete: 'deleteBehavior', deleteRule: 'deleteBehavior', cascade: 'deleteBehavior',
     formula: 'expression', calculation: 'expression', compute: 'expression',
-    rollup: 'summaryOperations', rollUp: 'summaryOperations', summary: 'summaryOperations', aggregate: 'summaryOperations',
+    // `rollup` alone covers `rollUp` / `roll_up` / `Roll-Up` — `aliasProbe`
+    // folds case and separators, so a second spelling was never reachable
+    // (#5481).
+    rollup: 'summaryOperations', summary: 'summaryOperations', aggregate: 'summaryOperations',
     length: 'maxLength', size: 'maxLength',
     decimals: 'scale', decimalPlaces: 'scale', digits: 'precision',
     isReadonly: 'readonly', disabled: 'readonly',
diff --git a/packages/spec/src/shared/alias-integrity.test.ts b/packages/spec/src/shared/alias-integrity.test.ts
index 19f13ad853..e04339a89a 100644
--- a/packages/spec/src/shared/alias-integrity.test.ts
+++ b/packages/spec/src/shared/alias-integrity.test.ts
@@ -54,8 +54,24 @@
  * - Tables reaching `strictUnknownKeyError` directly, which carry a transcribed
  *   `knownKeys` array instead of a shape — measured clean, pinned shrink-only
  *   below, extension tracked as #5483.
- * - Two alias keys in one table colliding under the suggester's own
- *   `aliasProbe` normalisation, where the later entry silently wins (#5481).
+ *
+ * ## The third claim (#5481)
+ *
+ * The two claims above are about a table and its *schema*. The third is about a
+ * table and *itself*: `strictUnknownKeyError` indexes the alias table by
+ * `aliasProbe(key)`, so two keys in one table that normalise identically
+ * collapse — **the later one silently wins**. That is not a stylistic
+ * redundancy. `these snap settings` listed `grid: 'gridSize'` and, at the end
+ * of the same table, `grid_: 'showGrid'`; the probe strips `_`, so `grid: 24`
+ * was answered *"Did you mean `grid` → `showGrid`?"* and `showGrid` is a
+ * boolean — a second rejection, ledger finding 7's exact shape, from a table
+ * whose author had written the correct mapping one line earlier.
+ *
+ * The other three instances on `main` pointed both keys at the same target, so
+ * the overwrite changed nothing and nobody could trip on them — which is the
+ * general lesson rather than an exemption: since the probe already folds case
+ * and separators, a second spelling of one probe is **never** reachable. It is
+ * dead either way; it is only sometimes also a defect.
  */
 
 import fs from 'node:fs';
@@ -65,6 +81,7 @@ import { fileURLToPath, pathToFileURL } from 'node:url';
 import { describe, it, expect, beforeAll } from 'vitest';
 import ts from 'typescript';
 
+import { aliasProbe } from './alias-probe';
 import { acceptsNothing, strictObjectDeclarations, type StrictObjectDeclaration } from './strict-object';
 
 const HERE = path.dirname(fileURLToPath(import.meta.url));
@@ -377,6 +394,33 @@ describe('alias integrity — every table is a true claim about its schema', ()
     expect(broken.sort()).toEqual([]);
   });
 
+  it('no two alias keys in one table collapse onto the same probe (#5481)', () => {
+    // The table is indexed by `aliasProbe(key)`, so a colliding pair does not
+    // produce two entries — it produces one, decided by source order, with the
+    // earlier key gone before any author can reach it. Judged with the REAL
+    // probe (imported, not transcribed): a gate carrying its own copy of the
+    // expression would keep passing if the normalisation ever widened.
+    const collisions: string[] = [];
+    for (const s of SURFACES) {
+      const byProbe = new Map<string, string[]>();
+      for (const key of Object.keys(s.options.aliases ?? {})) {
+        byProbe.set(aliasProbe(key), [...(byProbe.get(aliasProbe(key)) ?? []), key]);
+      }
+      for (const [probe, keys] of byProbe) {
+        if (keys.length < 2) continue;
+        // Name the winner explicitly. When the targets differ this is the whole
+        // defect (`grid` lost `gridSize` to `showGrid`); when they agree the
+        // entry is merely dead, and the fix is the same — keep one spelling.
+        const written = keys.map((k) => `\`${k}\` -> \`${s.options.aliases?.[k]}\``).join(', ');
+        collisions.push(
+          `${entry(s, keys[0], s.options.aliases?.[keys[0]] ?? '?')} — ${keys.length} keys share the probe \`${probe}\`: ${written}`
+          + ` — only \`${s.options.aliases?.[keys[keys.length - 1]]}\` survives`,
+        );
+      }
+    }
+    expect(collisions.sort()).toEqual([]);
+  });
+
   it('no guidance key is itself a declared key (the same dead entry, other channel)', () => {
     // `guidance` is consulted from the same `unrecognized_keys` path, so a
     // prescription filed under a key the shape DECLARES is unreachable in
diff --git a/packages/spec/src/shared/alias-probe.ts b/packages/spec/src/shared/alias-probe.ts
new file mode 100644
index 0000000000..0d493205fc
--- /dev/null
+++ b/packages/spec/src/shared/alias-probe.ts
@@ -0,0 +1,21 @@
+// Copyright (c) 2026 ObjectStack. Licensed under the Apache-2.0 license.
+
+/**
+ * The normalisation an alias table's keys are indexed under (#5481).
+ *
+ * This lives in its own leaf module for one reason: **two readers must agree.**
+ * `strictUnknownKeyError` folds every alias key through it to build the lookup
+ * a rejected key is answered from, and `alias-integrity.test.ts` folds the same
+ * keys through it to prove no two of them collide. A hand-copied regex in the
+ * gate would be a second copy of the truth — the exact shape #5013 and #5481
+ * were both filed against — and it would fail silently: widen the probe here
+ * (strip `.`, fold plurals) and a gate carrying the old expression keeps
+ * passing over collisions that now exist.
+ *
+ * It is deliberately **not** re-exported from `shared/index.ts`. Like
+ * `strict-object.ts`'s `strictObjectDeclarations`, it is an internal seam the
+ * gate reaches by relative path, not part of the `@objectstack/spec` contract.
+ */
+
+/** `reference_to` / `referenceTo` / `Reference-To` all collapse onto one probe. */
+export const aliasProbe = (key: string): string => key.toLowerCase().replace(/[_\-\s]/g, '');
diff --git a/packages/spec/src/shared/strict-object.test.ts b/packages/spec/src/shared/strict-object.test.ts
index 086ce75536..bf2f6bdf77 100644
--- a/packages/spec/src/shared/strict-object.test.ts
+++ b/packages/spec/src/shared/strict-object.test.ts
@@ -57,6 +57,22 @@ describe('strictObject', () => {
     expect(r.error!.issues[0].message).toContain('`visibleWhen` → `visible`');
   });
 
+  it('ONE alias entry already covers every case/separator spelling of itself (#5481)', () => {
+    // The fact that makes a second spelling of the same probe not merely
+    // redundant but unreachable: the table is indexed by `aliasProbe`, which
+    // folds case, `_`, `-` and spaces. Three tables on `main` carried a second
+    // spelling (`rollup`/`rollUp`, `object_name`/`objectName`,
+    // `strokeDasharray`/`strokeDashArray`) that could never have fired — the
+    // later one simply overwrote the earlier at the same index. Deleting them
+    // is behaviour-preserving, and this is the assertion that says so.
+    for (const spelling of ['visible_when', 'VISIBLE-WHEN', 'Visible When', 'visiblewhen']) {
+      const r = WidgetSchema.safeParse({ name: 'x', [spelling]: true });
+      expect(r.success, `${spelling} should be rejected`).toBe(false);
+      expect(r.error!.issues[0].message, `${spelling} should still reach the alias`)
+        .toContain(`\`${spelling}\` → \`visible\``);
+    }
+  });
+
   it('still honours a tombstone, and suppresses the rename for it', () => {
     const r = WidgetSchema.safeParse({ name: 'x', span: 2 });
     const msg = r.error!.issues[0].message;
diff --git a/packages/spec/src/shared/suggestions.zod.ts b/packages/spec/src/shared/suggestions.zod.ts
index 6d48bcf444..740ebbffce 100644
--- a/packages/spec/src/shared/suggestions.zod.ts
+++ b/packages/spec/src/shared/suggestions.zod.ts
@@ -3,6 +3,8 @@
 import type { z } from 'zod';
 import { FieldType } from '../data/field.zod';
 
+import { aliasProbe } from './alias-probe';
+
 /**
  * "Did you mean?" Suggestion Utilities
  *
@@ -216,9 +218,6 @@ export function formatSuggestion(suggestions: string[]): string {
   return `Did you mean one of: ${suggestions.map((s) => `'${s}'`).join(', ')}?`;
 }
 
-/** `reference_to` / `referenceTo` / `Reference-To` all collapse onto one probe. */
-const aliasProbe = (key: string): string => key.toLowerCase().replace(/[_\-\s]/g, '');
-
 /** Options for {@link strictUnknownKeyError}. */
 export interface StrictUnknownKeyErrorOptions {
   /** Prose name of the authoring surface the key was written on (e.g. `'this permission set'`). */
@@ -273,6 +272,14 @@ export function strictUnknownKeyError(options: StrictUnknownKeyErrorOptions): z.
   const { surface, knownKeys, guidance = {}, history } = options;
   const aliases: Record<string, string> = {};
   for (const [key, canonical] of Object.entries(options.aliases ?? {})) {
+    // Two keys in ONE table that share a probe collapse here, later silently
+    // winning — which pointed `snap.grid` at the boolean `showGrid` instead of
+    // `gridSize` until #5481. Nothing can be recovered at this point (the
+    // colliding key is already gone), so the defect is caught where it is
+    // authored: `alias-integrity.test.ts` rejects any table with two keys
+    // sharing an `aliasProbe`. Since the probe already eats case and
+    // separators, such a pair is redundant even when both point at the same
+    // target — one entry always covered both spellings.
     aliases[aliasProbe(key)] = canonical;
   }
   return (issue) => {
diff --git a/packages/spec/src/studio/flow-builder.test.ts b/packages/spec/src/studio/flow-builder.test.ts
index 5e3564f703..3fb24e7adf 100644
--- a/packages/spec/src/studio/flow-builder.test.ts
+++ b/packages/spec/src/studio/flow-builder.test.ts
@@ -217,6 +217,28 @@ describe('FlowBuilderConfigSchema', () => {
     expect(config.nodeDescriptors).toHaveLength(1);
     expect(config.undoLimit).toBe(100);
   });
+
+  it('answers `snap.grid` with `gridSize`, and the advice actually parses (#5481)', () => {
+    // A `grid_: 'showGrid'` entry used to sit after `grid: 'gridSize'` in this
+    // table; `aliasProbe` strips `_`, so the two shared one index and the later
+    // one won. An author writing `grid: 24` — the pixel pitch — was pointed at
+    // `showGrid`, a boolean, and rejected a second time for taking the advice.
+    const rejected = FlowBuilderConfigSchema.safeParse({ snap: { grid: 24 } });
+    expect(rejected.success).toBe(false);
+    const message = rejected.error!.issues[0].message;
+    expect(message).toContain('`grid` → `gridSize`');
+    expect(message).not.toContain('showGrid');
+
+    // The half that makes it a fix rather than a reworded rejection: doing what
+    // the message says has to work.
+    const followed = FlowBuilderConfigSchema.safeParse({ snap: { gridSize: 24 } });
+    expect(followed.success).toBe(true);
+    expect(followed.data!.snap.gridSize).toBe(24);
+
+    // `visible` still carries the show/hide intent `grid_` was reaching for.
+    const visible = FlowBuilderConfigSchema.safeParse({ snap: { visible: false } });
+    expect(visible.error!.issues[0].message).toContain('`visible` → `showGrid`');
+  });
 });
 
 // ---------------------------------------------------------------------------
diff --git a/packages/spec/src/studio/flow-builder.zod.ts b/packages/spec/src/studio/flow-builder.zod.ts
index bf3fda8d75..fb1d29228e 100644
--- a/packages/spec/src/studio/flow-builder.zod.ts
+++ b/packages/spec/src/studio/flow-builder.zod.ts
@@ -241,7 +241,13 @@ export const FlowBuilderConfigSchema = lazySchema(() => strictObject({
   snap: strictObject({
     surface: 'these snap settings',
     history: FLOW_BUILDER_HISTORY,
-    aliases: { active: 'enabled', on: 'enabled', grid: 'gridSize', size: 'gridSize', step: 'gridSize', visible: 'showGrid', grid_: 'showGrid' },
+    // `grid` points at `gridSize`, NOT at `showGrid`: an author writing `grid`
+    // on a snap config is reaching for the pixel pitch, and `visible` already
+    // carries the show/hide intent. A `grid_: 'showGrid'` entry used to sit at
+    // the end of this table and, because `aliasProbe` strips `_`, overwrote
+    // `grid` — so `grid: 24` was answered "Did you mean `grid` → `showGrid`?"
+    // and `showGrid` is a boolean, rejecting 24 a second time (#5481).
+    aliases: { active: 'enabled', on: 'enabled', grid: 'gridSize', size: 'gridSize', step: 'gridSize', visible: 'showGrid' },
   }, {
     enabled: z.boolean().default(true).describe('Enable snap-to-grid'),
     gridSize: z.number().int().min(1).default(16).describe('Snap grid size in pixels'),
diff --git a/packages/spec/src/ui/chart.zod.ts b/packages/spec/src/ui/chart.zod.ts
index 484ff9991d..274094b8aa 100644
--- a/packages/spec/src/ui/chart.zod.ts
+++ b/packages/spec/src/ui/chart.zod.ts
@@ -209,7 +209,8 @@ export const ChartSeriesSchema = lazySchema(() => strictObject(
       stackId: 'stack', stackGroup: 'stack', group: 'stack',
       axis: 'yAxis', yAxisId: 'yAxis', side: 'yAxis',
       role: 'variant',
-      strokeDasharray: 'dashArray', strokeDashArray: 'dashArray', dashed: 'dashArray',
+      // Recharts' own casing alone covers `strokeDashArray` — one probe (#5481).
+      strokeDasharray: 'dashArray', dashed: 'dashArray',
       alpha: 'opacity', fillOpacity: 'opacity', strokeOpacity: 'opacity',
       colour: 'color', fill: 'color', stroke: 'color',
     },