diff --git a/src/components/chat-components/RelevantNotes.tsx b/src/components/chat-components/RelevantNotes.tsx
index 70b5466c..3c4eaa88 100644
--- a/src/components/chat-components/RelevantNotes.tsx
+++ b/src/components/chat-components/RelevantNotes.tsx
@@ -10,7 +10,7 @@ import { useNoteDrag } from "@/hooks/useNoteDrag";
 import { cn } from "@/lib/utils";
 import { logWarn } from "@/logger";
 import { SemanticSearchToggleModal } from "@/components/modals/SemanticSearchToggleModal";
-import type { CopilotSettings } from "@/settings/model";
+import { shouldUseMiyo } from "@/miyo/miyoUtils";
 import {
   findRelevantNotes,
   getSimilarityCategory,
@@ -30,30 +30,6 @@ import {
 import { Notice, TFile } from "obsidian";
 import React, { memo, useCallback, useEffect, useState } from "react";
 
-const SELF_HOST_GRACE_PERIOD_MS = 15 * 24 * 60 * 60 * 1000;
-
-/**
- * Return true when Miyo-backed semantic index is expected to be active.
- *
- * @param settings - Current Copilot settings object.
- * @returns True when Miyo mode and self-host validation are active.
- */
-function shouldUseMiyoIndex(settings: CopilotSettings): boolean {
-  if (!settings.enableMiyo || !settings.enableSemanticSearchV3) {
-    return false;
-  }
-
-  if (settings.selfHostModeValidatedAt == null) {
-    return false;
-  }
-
-  if ((settings.selfHostValidationCount ?? 0) >= 3) {
-    return true;
-  }
-
-  return Date.now() - settings.selfHostModeValidatedAt < SELF_HOST_GRACE_PERIOD_MS;
-}
-
 function useRelevantNotes(refresher: number) {
   const [relevantNotes, setRelevantNotes] = useState<RelevantNoteEntry[]>([]);
   const [signalTick, setSignalTick] = useState(0);
@@ -93,9 +69,9 @@ function useHasIndex(notePath: string, refresher: number) {
         const VectorStoreManager = (await import("@/search/vectorStoreManager")).default;
         const { getSettings } = await import("@/settings/model");
         const settings = getSettings();
-        const shouldUseMiyo = shouldUseMiyoIndex(settings);
+        const useMiyo = shouldUseMiyo(settings);
 
-        if (shouldUseMiyo) {
+        if (useMiyo) {
           const isEmpty = await VectorStoreManager.getInstance().isIndexEmpty();
           setHasIndex(!isEmpty);
           return;
diff --git a/src/miyo/miyoUtils.ts b/src/miyo/miyoUtils.ts
index 11c493af..dce29aad 100644
--- a/src/miyo/miyoUtils.ts
+++ b/src/miyo/miyoUtils.ts
@@ -1,5 +1,6 @@
+import { isSelfHostAccessValid } from "@/plusUtils";
 import { CopilotSettings, getSettings } from "@/settings/model";
-import { App, FileSystemAdapter } from "obsidian";
+import { App, FileSystemAdapter, Platform } from "obsidian";
 
 /**
  * Return the user-configured Miyo server URL, or "" to fall back to local service discovery.
@@ -12,6 +13,28 @@ export function getMiyoCustomUrl(settings: CopilotSettings): string {
   return (settings.miyoServerUrl || "").trim();
 }
 
+/**
+ * Single source of truth for whether Miyo should be used.
+ *
+ * Returns false when:
+ * - `enableMiyo` is off, or
+ * - self-host access is invalid, or
+ * - running on mobile without a remote server URL (local service discovery
+ *   is unavailable on mobile, so Miyo can only work via an explicit URL).
+ *
+ * Note: `enableSemanticSearchV3` need not be checked — the UI enforces that
+ * enabling Miyo also enables semantic search, and disabling semantic search
+ * also disables Miyo.
+ *
+ * @param settings - Current Copilot settings.
+ */
+export function shouldUseMiyo(settings: CopilotSettings): boolean {
+  if (!settings.enableMiyo || !isSelfHostAccessValid()) {
+    return false;
+  }
+  return !Platform.isMobile || !!getMiyoCustomUrl(settings);
+}
+
 /**
  * Resolve the vault identifier sent to Miyo.
  *
diff --git a/src/search/RetrieverFactory.ts b/src/search/RetrieverFactory.ts
index ba57247c..b2c39d33 100644
--- a/src/search/RetrieverFactory.ts
+++ b/src/search/RetrieverFactory.ts
@@ -1,5 +1,6 @@
 import { logInfo, logWarn } from "@/logger";
-import { isSelfHostAccessValid, isSelfHostModeValid } from "@/plusUtils";
+import { isSelfHostModeValid } from "@/plusUtils";
+import { shouldUseMiyo } from "@/miyo/miyoUtils";
 import { getSettings, CopilotSettings } from "@/settings/model";
 import { App } from "obsidian";
 import { SelfHostRetriever, VectorSearchBackend } from "./selfHostRetriever";
@@ -323,7 +324,7 @@ export class RetrieverFactory {
    * @returns True when Miyo should be used for semantic retrieval.
    */
   private static shouldUseMiyo(settings: CopilotSettings): boolean {
-    return settings.enableMiyo && settings.enableSemanticSearchV3 && isSelfHostAccessValid();
+    return shouldUseMiyo(settings);
   }
 
   /**
diff --git a/src/search/findRelevantNotes.test.ts b/src/search/findRelevantNotes.test.ts
index 4346b079..5187b9da 100644
--- a/src/search/findRelevantNotes.test.ts
+++ b/src/search/findRelevantNotes.test.ts
@@ -2,9 +2,8 @@ import { TFile } from "obsidian";
 import { getBacklinkedNotes, getLinkedNotes } from "@/noteUtils";
 import { findRelevantNotes } from "@/search/findRelevantNotes";
 import { MiyoClient } from "@/miyo/MiyoClient";
-import { getMiyoVault } from "@/miyo/miyoUtils";
+import { getMiyoVault, shouldUseMiyo } from "@/miyo/miyoUtils";
 import { getSettings } from "@/settings/model";
-import { isSelfHostAccessValid } from "@/plusUtils";
 import VectorStoreManager from "@/search/vectorStoreManager";
 
 jest.mock("@/noteUtils", () => ({
@@ -50,10 +49,7 @@ jest.mock("@/miyo/MiyoClient", () => ({
 jest.mock("@/miyo/miyoUtils", () => ({
   getMiyoVault: jest.fn(),
   getMiyoCustomUrl: jest.fn().mockReturnValue(""),
-}));
-
-jest.mock("@/plusUtils", () => ({
-  isSelfHostAccessValid: jest.fn(),
+  shouldUseMiyo: jest.fn(),
 }));
 
 jest.mock("@/logger", () => ({
@@ -75,9 +71,7 @@ function createMarkdownFile(path: string): TFile {
 
 describe("findRelevantNotes", () => {
   const mockedGetSettings = getSettings as jest.MockedFunction<typeof getSettings>;
-  const mockedIsSelfHostAccessValid = isSelfHostAccessValid as jest.MockedFunction<
-    typeof isSelfHostAccessValid
-  >;
+  const mockedShouldUseMiyo = shouldUseMiyo as jest.MockedFunction<typeof shouldUseMiyo>;
   const mockedGetLinkedNotes = getLinkedNotes as jest.MockedFunction<typeof getLinkedNotes>;
   const mockedGetBacklinkedNotes = getBacklinkedNotes as jest.MockedFunction<
     typeof getBacklinkedNotes
@@ -93,7 +87,7 @@ describe("findRelevantNotes", () => {
 
   beforeEach(() => {
     jest.clearAllMocks();
-    mockedIsSelfHostAccessValid.mockReturnValue(false);
+    mockedShouldUseMiyo.mockReturnValue(false);
     mockedGetSettings.mockReturnValue({
       debug: false,
       miyoServerUrl: "",
@@ -180,7 +174,7 @@ describe("findRelevantNotes", () => {
   });
 
   it("uses Miyo when shouldUseMiyoForRelevantNotes is true (enableMiyo=true and valid self-host)", async () => {
-    mockedIsSelfHostAccessValid.mockReturnValue(true);
+    mockedShouldUseMiyo.mockReturnValue(true);
     mockedGetSettings.mockReturnValue({
       debug: false,
       miyoServerUrl: "http://127.0.0.1:8742",
@@ -256,7 +250,7 @@ describe("findRelevantNotes", () => {
   });
 
   it("falls back to link-only relevance when Miyo related-note search fails", async () => {
-    mockedIsSelfHostAccessValid.mockReturnValue(true);
+    mockedShouldUseMiyo.mockReturnValue(true);
     mockedGetSettings.mockReturnValue({
       debug: false,
       miyoServerUrl: "http://127.0.0.1:8742",
diff --git a/src/search/findRelevantNotes.ts b/src/search/findRelevantNotes.ts
index 77fec2da..02f4d8e4 100644
--- a/src/search/findRelevantNotes.ts
+++ b/src/search/findRelevantNotes.ts
@@ -1,12 +1,11 @@
 import { logInfo, logWarn } from "@/logger";
 import { MiyoClient } from "@/miyo/MiyoClient";
-import { getMiyoCustomUrl, getMiyoVault } from "@/miyo/miyoUtils";
+import { getMiyoCustomUrl, getMiyoVault, shouldUseMiyo } from "@/miyo/miyoUtils";
 import { getBacklinkedNotes, getLinkedNotes } from "@/noteUtils";
 import { DBOperations } from "@/search/dbOperations";
 import type { SemanticIndexDocument } from "@/search/indexBackend/SemanticIndexBackend";
 import VectorStoreManager from "@/search/vectorStoreManager";
 import { getSettings } from "@/settings/model";
-import { isSelfHostAccessValid } from "@/plusUtils";
 import { InternalTypedDocument, Orama, Result } from "@orama/orama";
 import { TFile } from "obsidian";
 
@@ -20,8 +19,7 @@ const LINKS_WEIGHT = 0.3;
  * @returns True when Miyo mode and self-host access validation are active.
  */
 function shouldUseMiyoForRelevantNotes(): boolean {
-  const settings = getSettings();
-  return settings.enableMiyo && settings.enableSemanticSearchV3 && isSelfHostAccessValid();
+  return shouldUseMiyo(getSettings());
 }
 
 /**
diff --git a/src/search/vectorStoreManager.ts b/src/search/vectorStoreManager.ts
index 97a344aa..5b0d7772 100644
--- a/src/search/vectorStoreManager.ts
+++ b/src/search/vectorStoreManager.ts
@@ -4,7 +4,7 @@ import { updateIndexingProgressState } from "@/aiParams";
 import { CustomError } from "@/error";
 import { logInfo, logWarn } from "@/logger";
 import EmbeddingsManager from "@/LLMProviders/embeddingManager";
-import { isSelfHostAccessValid } from "@/plusUtils";
+import { shouldUseMiyo } from "@/miyo/miyoUtils";
 import { CopilotSettings, getSettings, subscribeToSettingsChange } from "@/settings/model";
 import { Orama } from "@orama/orama";
 import { Notice, Platform, TFile } from "obsidian";
@@ -211,7 +211,7 @@ export default class VectorStoreManager {
    * @returns True when Miyo should be the active backend.
    */
   private shouldUseMiyo(settings: CopilotSettings): boolean {
-    return settings.enableMiyo && settings.enableSemanticSearchV3 && isSelfHostAccessValid();
+    return shouldUseMiyo(settings);
   }
 
   /**