diff --git a/packages/web-components/src/components/dotcom-shell/dotcom-shell-container.ts b/packages/web-components/src/components/dotcom-shell/dotcom-shell-container.ts
index e499f1bdbfd..8a6344b986e 100644
--- a/packages/web-components/src/components/dotcom-shell/dotcom-shell-container.ts
+++ b/packages/web-components/src/components/dotcom-shell/dotcom-shell-container.ts
@@ -1,7 +1,7 @@
 /**
  * @license
  *
- * Copyright IBM Corp. 2020, 2023
+ * Copyright IBM Corp. 2020, 2024
  *
  * This source code is licensed under the Apache-2.0 license found in the
  * LICENSE file in the root directory of this source tree.
@@ -29,6 +29,7 @@ import {
   mapStateToProps as mapStateToPropsMasthead,
   mapDispatchToProps as mapDispatchToPropsMasthead,
 } from '../masthead/masthead-container';
+import C4DMastheadComposite from '../masthead/masthead-composite';
 import C4DDotcomShellComposite from './dotcom-shell-composite';
 import { carbonElement as customElement } from '../../internal/vendor/@carbon/web-components/globals/decorators/carbon-element';
 
@@ -60,11 +61,12 @@ export type DotcomShellContainerActions =
  * @returns The converted version of the given state, tailored for `<c4d-dotcomshell-container>`.
  */
 export function mapStateToProps(
-  state: MastheadContainerState & FooterContainerState
+  state: MastheadContainerState & FooterContainerState,
+  self: C4DMastheadComposite
 ): MastheadContainerStateProps & FooterContainerStateProps {
   const footerProps = mapStateToPropsFooter(state);
   return {
-    ...mapStateToPropsMasthead(state),
+    ...mapStateToPropsMasthead(state, self),
     ...Object.keys(footerProps).reduce((acc, key) => {
       acc[key !== 'links' ? key : 'footerLinks'] = footerProps[key];
       return acc;
diff --git a/packages/web-components/src/components/masthead/__stories__/masthead.stories.ts b/packages/web-components/src/components/masthead/__stories__/masthead.stories.ts
index f79032af8e8..5dc7ef928ce 100644
--- a/packages/web-components/src/components/masthead/__stories__/masthead.stories.ts
+++ b/packages/web-components/src/components/masthead/__stories__/masthead.stories.ts
@@ -104,7 +104,7 @@ export const Default = (args) => {
     </style>
     ${useMock
       ? html`
-          <c4d-masthead-composite
+          <c4d-masthead-container
             selected-menu-item="${ifDefined(selectedMenuItem)}"
             user-status="${ifDefined(userStatus)}"
             searchPlaceholder="${ifDefined(searchPlaceholder)}"
@@ -117,7 +117,7 @@ export const Default = (args) => {
               unauthenticatedProfileItems
             )}"
             custom-profile-login="${customProfileLogin}"
-            auth-method="${MASTHEAD_AUTH_METHOD.DEFAULT}"></c4d-masthead-composite>
+            auth-method="${MASTHEAD_AUTH_METHOD.DEFAULT}"></c4d-masthead-container>
         `
       : html`
           <c4d-masthead-container
@@ -155,7 +155,7 @@ export const WithCustomTypeahead = (args) => {
     </style>
     ${useMock
       ? html`
-          <c4d-masthead-composite
+          <c4d-masthead-container
             .l0Data="${mastheadL0Data}"
             .authenticatedProfileItems="${ifNonEmpty(
               authenticatedProfileItems
@@ -163,7 +163,7 @@ export const WithCustomTypeahead = (args) => {
             .unauthenticatedProfileItems="${ifNonEmpty(
               unauthenticatedProfileItems
             )}"
-            ?custom-typeahead-api=${true}></c4d-masthead-composite>
+            ?custom-typeahead-api=${true}></c4d-masthead-container>
         `
       : html`
           <c4d-masthead-container
@@ -201,7 +201,7 @@ export const searchOpenOnload = (args) => {
     </style>
     ${useMock
       ? html`
-          <c4d-masthead-composite
+          <c4d-masthead-container
             .l0Data="${mastheadL0Data}"
             .authenticatedProfileItems="${ifNonEmpty(
               authenticatedProfileItems
@@ -212,7 +212,7 @@ export const searchOpenOnload = (args) => {
             activate-search="true"
             searchPlaceholder="${ifDefined(
               searchPlaceholder
-            )}"></c4d-masthead-composite>
+            )}"></c4d-masthead-container>
         `
       : html`
           <c4d-masthead-container
@@ -247,7 +247,7 @@ export const withPlatform = (args) => {
     </style>
     ${useMock
       ? html`
-          <c4d-masthead-composite
+          <c4d-masthead-container
             platform="${ifNonEmpty(platform)}"
             .l0Data="${mastheadL0Data}"
             .authenticatedProfileItems="${ifNonEmpty(
@@ -256,7 +256,7 @@ export const withPlatform = (args) => {
             .unauthenticatedProfileItems="${ifNonEmpty(
               unauthenticatedProfileItems
             )}"
-            .platformUrl="${ifNonEmpty(platformUrl)}"></c4d-masthead-composite>
+            .platformUrl="${ifNonEmpty(platformUrl)}"></c4d-masthead-container>
         `
       : html`
           <c4d-masthead-container
@@ -313,7 +313,7 @@ export const withL1 = (args) => {
     </style>
     ${useMock
       ? html`
-          <c4d-masthead-composite
+          <c4d-masthead-container
             .l0Data="${mastheadL0Data}"
             .authenticatedProfileItems="${ifNonEmpty(
               authenticatedProfileItems
@@ -325,7 +325,7 @@ export const withL1 = (args) => {
             selected-menu-item="${ifNonEmpty(selectedMenuItem)}"
             selected-menu-item-l1="${ifNonEmpty(
               selectedMenuItemL1
-            )}"></c4d-masthead-composite>
+            )}"></c4d-masthead-container>
         `
       : html`
           <c4d-masthead-container
@@ -377,7 +377,7 @@ export const withAlternateLogoAndTooltip = (args) => {
     </style>
     ${useMock
       ? html`
-          <c4d-masthead-composite
+          <c4d-masthead-container
             .l0Data="${mastheadL0Data}"
             .authenticatedProfileItems="${ifNonEmpty(
               authenticatedProfileItems
@@ -387,7 +387,7 @@ export const withAlternateLogoAndTooltip = (args) => {
             )}"
             .logoData="${mastheadLogo === 'alternateWithTooltip'
               ? mastheadLogoData
-              : null}"></c4d-masthead-composite>
+              : null}"></c4d-masthead-container>
         `
       : html`
           <c4d-masthead-container
@@ -437,7 +437,7 @@ export const WithScopedSearch = (args) => {
     </style>
     ${useMock
       ? html`
-          <c4d-masthead-composite
+          <c4d-masthead-container
             .l0Data="${mastheadL0Data}"
             .authenticatedProfileItems="${ifNonEmpty(
               authenticatedProfileItems
@@ -445,7 +445,7 @@ export const WithScopedSearch = (args) => {
             .unauthenticatedProfileItems="${ifNonEmpty(
               unauthenticatedProfileItems
             )}"
-            .scopeParameters=${scopeParameters}></c4d-masthead-composite>
+            .scopeParameters=${scopeParameters}></c4d-masthead-container>
         `
       : html`
           <c4d-masthead-container
diff --git a/packages/web-components/src/components/masthead/masthead-container.ts b/packages/web-components/src/components/masthead/masthead-container.ts
index dccf53e6edd..34e82f82d39 100644
--- a/packages/web-components/src/components/masthead/masthead-container.ts
+++ b/packages/web-components/src/components/masthead/masthead-container.ts
@@ -84,21 +84,24 @@ export type MastheadContainerActions =
 
 /**
  * @param state The Redux state for masthead.
+ * @param self A reference to the masthead composite instance.
  * @returns The converted version of the given state, tailored for `<c4d-masthead-container>`.
  */
 export function mapStateToProps(
-  state: MastheadContainerState
+  state: MastheadContainerState,
+  self: C4DMastheadComposite
 ): MastheadContainerStateProps {
   const { localeAPI, translateAPI, profileAPI } = state;
   const { language } = localeAPI ?? {};
   const { translations } = translateAPI ?? {};
   const { request } = profileAPI ?? {};
+  const { l0Data: userL0Data } = self;
 
   // Attempt to collect data from current/new and deprecated locations.
-  let l0Data;
+  let endpointl0Data;
   let profileItems;
   if (language) {
-    l0Data = {
+    endpointl0Data = {
       current: translations?.[language]?.masthead?.nav,
       deprecated: translations?.[language]?.mastheadNav?.links,
     };
@@ -118,8 +121,11 @@ export function mapStateToProps(
 
   return pickBy(
     {
-      // Progressively enhance to new L0 data shape.
-      l0Data: !language ? undefined : l0Data.current || l0Data.deprecated,
+      // Respect user-set L0 data. Otherwise, progressively enhance to new shape.
+      l0Data:
+        !language || userL0Data
+          ? undefined
+          : endpointl0Data.current || endpointl0Data.deprecated,
       // Progressively enhance to new profile items shape.
       authenticatedProfileItems: !language
         ? undefined
diff --git a/packages/web-components/src/globals/mixins/connect.ts b/packages/web-components/src/globals/mixins/connect.ts
index 432c387c37a..8f62e33dd6a 100644
--- a/packages/web-components/src/globals/mixins/connect.ts
+++ b/packages/web-components/src/globals/mixins/connect.ts
@@ -1,7 +1,7 @@
 /**
  * @license
  *
- * Copyright IBM Corp. 2020, 2023
+ * Copyright IBM Corp. 2020, 2024
  *
  * This source code is licensed under the Apache-2.0 license found in the
  * LICENSE file in the root directory of this source tree.
@@ -13,7 +13,7 @@ import Handle from '../internal/handle';
 
 /**
  * @param store A redux store.
- * @returns A funciton that takes a base class and returns a mix-in that connects the component to Redux store.
+ * @returns A function that takes a base class and returns a mix-in that connects the component to Redux store.
  */
 const ConnectMixin =
   <
@@ -23,7 +23,7 @@ const ConnectMixin =
     TDispatchProps = { [name: string]: any }
   >(
     store: Store<TState, TAction>,
-    mapStateToProps: (state: TState) => TStateProps,
+    mapStateToProps: (state: TState, self?: any) => TStateProps,
     mapDispatchToProps: (dispatch: Dispatch<TAction>) => TDispatchProps = () =>
       ({} as TDispatchProps)
   ) =>
@@ -35,7 +35,7 @@ const ConnectMixin =
       _hStore: Handle | null = null;
 
       _handleChangeStoreState(state: TState) {
-        const props = mapStateToProps(state);
+        const props = mapStateToProps(state, this);
         Object.keys(props as any).forEach((name) => {
           const old = this[name];
           const current = props[name];