diff --git a/src/libs/OptionsListUtils.ts b/src/libs/OptionsListUtils.ts
index bb52686c4bd4..60d602838c70 100644
--- a/src/libs/OptionsListUtils.ts
+++ b/src/libs/OptionsListUtils.ts
@@ -244,17 +244,6 @@ Onyx.connect({
     },
 });
 
-const policyExpenseReports: OnyxCollection<Report> = {};
-Onyx.connect({
-    key: ONYXKEYS.COLLECTION.REPORT,
-    callback: (report, key) => {
-        if (!ReportUtils.isPolicyExpenseChat(report)) {
-            return;
-        }
-        policyExpenseReports[key] = report;
-    },
-});
-
 let allTransactions: OnyxCollection<Transaction> = {};
 Onyx.connect({
     key: ONYXKEYS.COLLECTION.TRANSACTION,
@@ -763,13 +752,13 @@ function getReportOption(participant: Participant): ReportUtils.OptionData {
 /**
  * Get the option for a policy expense report.
  */
-function getPolicyExpenseReportOption(report: Report): ReportUtils.OptionData {
-    const expenseReport = policyExpenseReports?.[`${ONYXKEYS.COLLECTION.REPORT}${report.reportID}`];
+function getPolicyExpenseReportOption(participant: Participant | ReportUtils.OptionData): ReportUtils.OptionData {
+    const expenseReport = ReportUtils.isPolicyExpenseChat(participant) ? ReportUtils.getReport(participant.reportID) : null;
 
     const option = createOption(
         expenseReport?.visibleChatMemberAccountIDs ?? [],
         allPersonalDetails ?? {},
-        expenseReport ?? null,
+        !isEmptyObject(expenseReport) ? expenseReport : null,
         {},
         {
             showChatPreviewLine: false,
@@ -780,8 +769,8 @@ function getPolicyExpenseReportOption(report: Report): ReportUtils.OptionData {
     // Update text & alternateText because createOption returns workspace name only if report is owned by the user
     option.text = ReportUtils.getPolicyName(expenseReport);
     option.alternateText = Localize.translateLocal('workspace.common.workspace');
-    option.selected = report.selected;
-    option.isSelected = report.selected;
+    option.selected = participant.selected;
+    option.isSelected = participant.selected;
     return option;
 }
 
diff --git a/src/libs/ReportActionsUtils.ts b/src/libs/ReportActionsUtils.ts
index 11f870b891b6..43145dc3c7a1 100644
--- a/src/libs/ReportActionsUtils.ts
+++ b/src/libs/ReportActionsUtils.ts
@@ -50,17 +50,12 @@ type MemberChangeMessageElement = MessageTextElement | MemberChangeMessageUserMe
 
 const policyChangeActionsSet = new Set<string>(Object.values(CONST.REPORT.ACTIONS.TYPE.POLICYCHANGELOG));
 
-const allReports: OnyxCollection<Report> = {};
-
+let allReports: OnyxCollection<Report> = {};
 Onyx.connect({
     key: ONYXKEYS.COLLECTION.REPORT,
-    callback: (report, key) => {
-        if (!key || !report) {
-            return;
-        }
-
-        const reportID = CollectionUtils.extractCollectionItemID(key);
-        allReports[reportID] = report;
+    waitForCollectionCallback: true,
+    callback: (reports) => {
+        allReports = reports;
     },
 });
 
diff --git a/src/libs/TaskUtils.ts b/src/libs/TaskUtils.ts
index 81a079003d0e..7cbc9f2dc1f8 100644
--- a/src/libs/TaskUtils.ts
+++ b/src/libs/TaskUtils.ts
@@ -1,22 +1,18 @@
-import type {OnyxEntry} from 'react-native-onyx';
+import type {OnyxCollection, OnyxEntry} from 'react-native-onyx';
 import Onyx from 'react-native-onyx';
 import CONST from '@src/CONST';
 import ONYXKEYS from '@src/ONYXKEYS';
 import type {Report} from '@src/types/onyx';
 import type {Message} from '@src/types/onyx/ReportAction';
 import type ReportAction from '@src/types/onyx/ReportAction';
-import * as CollectionUtils from './CollectionUtils';
 import * as Localize from './Localize';
 
-const allReports: Record<string, Report> = {};
+let allReports: OnyxCollection<Report> = {};
 Onyx.connect({
     key: ONYXKEYS.COLLECTION.REPORT,
-    callback: (report, key) => {
-        if (!key || !report) {
-            return;
-        }
-        const reportID = CollectionUtils.extractCollectionItemID(key);
-        allReports[reportID] = report;
+    waitForCollectionCallback: true,
+    callback: (reports) => {
+        allReports = reports;
     },
 });
 
@@ -42,11 +38,11 @@ function getTaskReportActionMessage(action: OnyxEntry<ReportAction>): Pick<Messa
 }
 
 function getTaskTitle(taskReportID: string, fallbackTitle = ''): string {
-    const taskReport = allReports[taskReportID] ?? {};
+    const taskReport = allReports?.[taskReportID] ?? {};
     // We need to check for reportID, not just reportName, because when a receiver opens the task for the first time,
     // an optimistic report is created with the only property – reportName: 'Chat report',
     // and it will be displayed as the task title without checking for reportID to be present.
-    return Object.hasOwn(taskReport, 'reportID') && taskReport.reportName ? taskReport.reportName : fallbackTitle;
+    return Object.hasOwn(taskReport, 'reportID') && 'reportName' in taskReport && typeof taskReport.reportName === 'string' ? taskReport.reportName : fallbackTitle;
 }
 
 function getTaskCreatedMessage(reportAction: OnyxEntry<ReportAction>) {
diff --git a/src/libs/actions/PriorityMode.ts b/src/libs/actions/PriorityMode.ts
index 7ae174ac8606..77347967b6cd 100644
--- a/src/libs/actions/PriorityMode.ts
+++ b/src/libs/actions/PriorityMode.ts
@@ -1,7 +1,6 @@
 import debounce from 'lodash/debounce';
 import type {OnyxCollection} from 'react-native-onyx';
 import Onyx from 'react-native-onyx';
-import * as CollectionUtils from '@libs/CollectionUtils';
 import Log from '@libs/Log';
 import * as ReportUtils from '@libs/ReportUtils';
 import CONST from '@src/CONST';
@@ -36,21 +35,12 @@ Onyx.connect({
 // eslint-disable-next-line @typescript-eslint/no-use-before-define
 const autoSwitchToFocusMode = debounce(tryFocusModeUpdate, 300, {leading: true});
 
-let allReports: OnyxCollection<Report> | undefined;
+let allReports: OnyxCollection<Report> | undefined = {};
 Onyx.connect({
     key: ONYXKEYS.COLLECTION.REPORT,
-    callback: (report, key) => {
-        if (!key || !report) {
-            return;
-        }
-
-        if (!allReports) {
-            allReports = {};
-        }
-
-        const reportID = CollectionUtils.extractCollectionItemID(key);
-
-        allReports[reportID] = report;
+    waitForCollectionCallback: true,
+    callback: (reports) => {
+        allReports = reports;
 
         // Each time a new report is added we will check to see if the user should be switched
         autoSwitchToFocusMode();
diff --git a/src/libs/actions/Report.ts b/src/libs/actions/Report.ts
index 8cea9cbd0dae..225022665ddc 100644
--- a/src/libs/actions/Report.ts
+++ b/src/libs/actions/Report.ts
@@ -136,6 +136,8 @@ Onyx.connect({
         }
         const reportID = CollectionUtils.extractCollectionItemID(key);
         currentReportData[reportID] = report;
+        // eslint-disable-next-line @typescript-eslint/no-use-before-define
+        handleReportChanged(report);
     },
 });
 
@@ -1126,11 +1128,6 @@ function handleReportChanged(report: OnyxEntry<Report>) {
     }
 }
 
-Onyx.connect({
-    key: ONYXKEYS.COLLECTION.REPORT,
-    callback: handleReportChanged,
-});
-
 /** Deletes a comment from the report, basically sets it as empty string */
 function deleteReportComment(reportID: string, reportAction: ReportAction) {
     const originalReportID = ReportUtils.getOriginalReportID(reportID, reportAction);
diff --git a/src/libs/actions/Welcome.ts b/src/libs/actions/Welcome.ts
index 89d607645fb6..150b23a4a0d9 100644
--- a/src/libs/actions/Welcome.ts
+++ b/src/libs/actions/Welcome.ts
@@ -82,16 +82,13 @@ Onyx.connect({
     },
 });
 
-const allReports: OnyxCollection<Report> = {};
+let allReports: OnyxCollection<Report> = {};
 Onyx.connect({
     key: ONYXKEYS.COLLECTION.REPORT,
     initWithStoredValues: false,
-    callback: (val, key) => {
-        if (!val || !key) {
-            return;
-        }
-
-        allReports[key] = {...allReports[key], ...val};
+    waitForCollectionCallback: true,
+    callback: (reports) => {
+        allReports = reports;
     },
 });
 
diff --git a/src/setup/index.ts b/src/setup/index.ts
index f79e6a461a3e..581dbd28056f 100644
--- a/src/setup/index.ts
+++ b/src/setup/index.ts
@@ -27,7 +27,7 @@ export default function () {
         keys: ONYXKEYS,
 
         // Increase the cached key count so that the app works more consistently for accounts with large numbers of reports
-        maxCachedKeysCount: 10000,
+        maxCachedKeysCount: 20000,
         safeEvictionKeys: [ONYXKEYS.COLLECTION.REPORT_ACTIONS],
         captureMetrics: Metrics.canCaptureOnyxMetrics(),
         initialKeyStates: {