diff --git a/libs/blocks/graybox/graybox.css b/libs/blocks/graybox/graybox.css
index 996d6fe560e..b115fefcc40 100644
--- a/libs/blocks/graybox/graybox.css
+++ b/libs/blocks/graybox/graybox.css
@@ -323,107 +323,3 @@
     border-radius: 5px;
   }
 }
-
-/* Spectrum Switch */
-.spectrum-Switch {
-    display: inline-flex;
-    align-items: flex-start;
-    position: relative;
-    margin: auto;
-    min-block-size: var(--mod-switch-height, var(--spectrum-switch-min-height));
-    max-inline-size: 100%;
-    vertical-align: top;
-}
-
-.spectrum-Switch.gb-toggle-disabled {
-  pointer-events: none;
-  opacity: 0.5;
-}
-
-/* .gb-toggle-disabled .spectrum-Switch {
-  pointer-events: none;
-} */
-
-.spectrum-Switch-input {
-    margin: 0;
-    box-sizing: border-box;
-    padding: 0;
-    position: absolute;
-    inline-size: 100%;
-    block-size: 100%;
-    inset-block-start: 0;
-    inset-inline-start: 0;
-    opacity: 0;
-    z-index: 1;
-    cursor: pointer;
-}
-
-.spectrum-Switch-switch {
-    display: inline-block;
-    box-sizing: border-box;
-    position: relative;
-    inline-size: 26px;
-    margin-block: 9px;
-    margin-inline: 0;
-    flex-grow: 0;
-    flex-shrink: 0;
-    vertical-align: middle;
-    transition: background 0.16s ease-in-out, border 0.16s ease-in-out;
-    block-size: 14px;
-    inset-inline-start: 0;
-    inset-inline-end: 0;
-    border-radius: 7px;
-    background-color: rgb(225 225 225);
-}
-
-.spectrum-Switch-switch::after, .spectrum-Switch-switch::before {
-    display: block;
-    position: absolute;
-    content: "";
-    inset-block-start: 0;
-    inset-inline-start: 0;
-}
-
-.spectrum-Switch-switch::before {
-    box-sizing: border-box;
-    transition: background 0.16s ease-in-out, border 0.16s ease-in-out, transform 0.13s ease-in-out, box-shadow 0.16s ease-in-out;
-    inline-size: 14px;
-    block-size: 14px;
-    border-width: 2px;
-    border-radius: 7px;
-    border-style: solid;
-    background-color: rgb(248 248 248);
-    border-color: rgb(113 113 113);
-}
-
-.spectrum-Switch-switch::after {
-    border-radius: 11px;
-    inset-inline-end: 0;
-    inset-block-end: 0;
-    margin: 0;
-    transition: opacity 0.16s ease-out, margin 0.16s ease-out;
-}
-
-.spectrum-Switch-label {
-    color: rgb(41 41 41);
-    margin-inline: 10px;
-    margin-block-start: 6px;
-    margin-block-end: 0;
-    font-size: 14px;
-    line-height: 1.3;
-    transition: color 0.16s ease-in-out;
-}
-
-.spectrum-Switch-input:checked+.spectrum-Switch-switch::before {
-    transform: translate(calc(26px - 100%));
-    border-color: rgb(80 80 80);
-}
-
-.spectrum-Switch:hover .spectrum-Switch-input+.spectrum-Switch-switch::before {
-    border-color: rgb(80 80 80);
-    box-shadow: none;
-}
-
-.spectrum-Switch-input:checked+.spectrum-Switch-switch {
-    background-color: rgb(41 41 41);
-}
diff --git a/libs/blocks/graybox/graybox.js b/libs/blocks/graybox/graybox.js
index cfced9e67f2..7579409999b 100644
--- a/libs/blocks/graybox/graybox.js
+++ b/libs/blocks/graybox/graybox.js
@@ -1,4 +1,4 @@
-import { createTag, getMetadata } from '../../utils/utils.js';
+import { createTag, getMetadata, loadStyle, getConfig } from '../../utils/utils.js';
 import { getModal, closeModal } from '../modal/modal.js';
 import { iphoneFrame, ipadFrame } from './mobileFrames.js';
 
@@ -323,6 +323,8 @@ const openDeviceModal = async (e) => {
 };
 
 const createGrayboxOverlayToggle = (grayboxMenu) => {
+  const { base } = getConfig();
+  loadStyle(`${base}/blocks/graybox/switch.css`);
   const switchDiv = createTag('div', { class: 'spectrum-Switch' }, null, { parent: grayboxMenu });
   const input = createTag('input', { type: 'checkbox', class: 'spectrum-Switch-input', id: 'gb-overlay-toggle' }, null, { parent: switchDiv });
   createTag('span', { class: 'spectrum-Switch-switch' }, null, { parent: switchDiv });
diff --git a/libs/blocks/graybox/switch.css b/libs/blocks/graybox/switch.css
new file mode 100644
index 00000000000..0b3000a39ff
--- /dev/null
+++ b/libs/blocks/graybox/switch.css
@@ -0,0 +1,109 @@
+.toggle-switch {
+  position: absolute;
+  top: 15px;
+  right: 25px;
+}
+
+.toggle-switch .spectrum-Switch:first-child {
+    margin-right: 15px;
+}
+
+/* Spectrum Switch */
+.spectrum-Switch {
+    display: inline-flex;
+    align-items: flex-start;
+    position: relative;
+    margin: auto;
+    min-block-size: var(--mod-switch-height, var(--spectrum-switch-min-height));
+    max-inline-size: 100%;
+    vertical-align: top;
+}
+
+.spectrum-Switch.gb-toggle-disabled {
+  pointer-events: none;
+  opacity: 0.5;
+}
+
+.spectrum-Switch-input {
+    margin: 0;
+    box-sizing: border-box;
+    padding: 0;
+    position: absolute;
+    inline-size: 100%;
+    block-size: 100%;
+    inset-block-start: 0;
+    inset-inline-start: 0;
+    opacity: 0;
+    z-index: 1;
+    cursor: pointer;
+}
+
+.spectrum-Switch-switch {
+    display: inline-block;
+    box-sizing: border-box;
+    position: relative;
+    inline-size: 26px;
+    margin-block: 9px;
+    margin-inline: 0;
+    flex-grow: 0;
+    flex-shrink: 0;
+    vertical-align: middle;
+    transition: background 0.16s ease-in-out, border 0.16s ease-in-out;
+    block-size: 14px;
+    inset-inline-start: 0;
+    inset-inline-end: 0;
+    border-radius: 7px;
+    background-color: rgb(225 225 225);
+}
+
+.spectrum-Switch-switch::after, .spectrum-Switch-switch::before {
+    display: block;
+    position: absolute;
+    content: "";
+    inset-block-start: 0;
+    inset-inline-start: 0;
+}
+
+.spectrum-Switch-switch::before {
+    box-sizing: border-box;
+    transition: background 0.16s ease-in-out, border 0.16s ease-in-out, transform 0.13s ease-in-out, box-shadow 0.16s ease-in-out;
+    inline-size: 14px;
+    block-size: 14px;
+    border-width: 2px;
+    border-radius: 7px;
+    border-style: solid;
+    background-color: rgb(248 248 248);
+    border-color: rgb(113 113 113);
+}
+
+.spectrum-Switch-switch::after {
+    border-radius: 11px;
+    inset-inline-end: 0;
+    inset-block-end: 0;
+    margin: 0;
+    transition: opacity 0.16s ease-out, margin 0.16s ease-out;
+}
+
+.spectrum-Switch-label {
+    color: rgb(41 41 41);
+    margin-inline: 10px;
+    margin-block-start: 6px;
+    margin-block-end: 0;
+    font-size: 14px;
+    line-height: 1.3;
+    transition: color 0.16s ease-in-out;
+}
+
+.spectrum-Switch-input:checked+.spectrum-Switch-switch::before {
+    transform: translate(calc(26px - 100%));
+    border-color: rgb(80 80 80);
+}
+
+.spectrum-Switch:hover .spectrum-Switch-input+.spectrum-Switch-switch::before {
+    border-color: rgb(80 80 80);
+    box-shadow: none;
+}
+
+.spectrum-Switch-input:checked+.spectrum-Switch-switch {
+    background-color: rgb(41 41 41);
+}
diff --git a/libs/blocks/ost/ost.js b/libs/blocks/ost/ost.js
index 9121fdc29f6..8aa490be6f1 100644
--- a/libs/blocks/ost/ost.js
+++ b/libs/blocks/ost/ost.js
@@ -1,5 +1,7 @@
 import ctaTextOption from './ctaTextOption.js';
-import { getConfig, getLocale, getMetadata, loadScript, loadStyle } from '../../utils/utils.js';
+import {
+  getConfig, getLocale, getMetadata, loadScript, loadStyle, createTag,
+} from '../../utils/utils.js';
 
 export const AOS_API_KEY = 'wcms-commerce-ims-user-prod';
 export const CHECKOUT_CLIENT_ID = 'creative';
@@ -14,6 +16,17 @@ const OST_STYLE_URL = 'https://mas.adobe.com/studio/ost/index.css';
 export const WCS_ENV = 'PROD';
 export const WCS_API_KEY = 'wcms-commerce-ims-ro-user-cc';
 export const WCS_LANDSCAPE = 'PUBLISHED';
+export const WCS_LANDSCAPE_DRAFT = 'DRAFT';
+export const LANDSCAPE_URL_PARAM = 'commerce.landscape';
+export const DEFAULTS_URL_PARAM = 'commerce.defaults';
+
+function isMasDefaultsEnabled() {
+  const searchParameters = new URLSearchParams(window.location.search);
+  const defaults = searchParameters.get(DEFAULTS_URL_PARAM) || 'on';
+  return defaults === 'on';
+}
+
+const masDefaultsEnabled = isMasDefaultsEnabled();
 
 /**
  * Maps Franklin page metadata to OST properties.
@@ -31,8 +44,10 @@ const priceDefaultOptions = {
   exclusive: false,
 };
 
-const updateParams = (params, key, value) => {
-  if (value !== priceDefaultOptions[key]) {
+const updateParams = (params, key, value, cs) => {
+  let defaultValue = priceDefaultOptions[key];
+  if (key === 'seat') defaultValue = cs !== 'INDIVIDUAL';
+  if (value !== defaultValue) {
     params.set(key, value);
   }
 };
@@ -78,7 +93,7 @@ export const createLinkMarkup = (
         forceTaxExclusive,
       } = options;
       updateParams(params, 'term', displayRecurrence);
-      updateParams(params, 'seat', displayPerUnit);
+      updateParams(params, 'seat', displayPerUnit, masDefaultsEnabled ? offer.customer_segment : null);
       updateParams(params, 'tax', displayTax);
       updateParams(params, 'old', displayOldPrice);
       updateParams(params, 'exclusive', forceTaxExclusive);
@@ -102,18 +117,22 @@ export async function loadOstEnv() {
   const commerceEnv = searchParameters.get('commerce.env');
   if (wcsLandscape || commerceEnv) {
     if (wcsLandscape) {
-      searchParameters.set('commerce.landscape', wcsLandscape);
+      searchParameters.set(LANDSCAPE_URL_PARAM, wcsLandscape);
       searchParameters.delete('wcsLandscape');
     }
     if (commerceEnv?.toLowerCase() === 'stage') {
-      searchParameters.set('commerce.landscape', 'DRAFT');
+      searchParameters.set(LANDSCAPE_URL_PARAM, WCS_LANDSCAPE_DRAFT);
       searchParameters.delete('commerce.env');
     }
     window.history.replaceState({}, null, `${window.location.origin}${window.location.pathname}?${searchParameters.toString()}`);
   }
   /* c8 ignore next */
   const { initService, loadMasComponent, getMasLibs, getMiloLocaleSettings, MAS_COMMERCE_SERVICE } = await import('../merch/merch.js');
-  await initService(true, { 'allow-override': 'true' });
+  const attributes = { 'allow-override': 'true' };
+  if (isMasDefaultsEnabled) {
+    attributes['data-mas-ff-defaults'] = 'on';
+  }
+  await initService(true, attributes);
   // Load commerce.js based on masLibs parameter
   await loadMasComponent(MAS_COMMERCE_SERVICE);
 
@@ -131,7 +150,7 @@ export async function loadOstEnv() {
 
   const defaultPlaceholderOptions = Object.fromEntries([
     ['term', 'displayRecurrence', 'true'],
-    ['seat', 'displayPerUnit', 'true'],
+    ['seat', 'displayPerUnit', masDefaultsEnabled ? null : 'true'],
     ['tax', 'displayTax'],
     ['old', 'displayOldPrice'],
   ].map(([key, targetKey, defaultValue = false]) => {
@@ -178,7 +197,7 @@ export async function loadOstEnv() {
   window.history.replaceState({}, null, newURL);
 
   const environment = searchParameters.get('env') ?? WCS_ENV;
-  const landscape = searchParameters.get('commerce.landscape') ?? WCS_LANDSCAPE;
+  const landscape = searchParameters.get(LANDSCAPE_URL_PARAM) ?? WCS_LANDSCAPE;
   const owner = searchParameters.get('owner');
   const referrer = searchParameters.get('referrer');
   const repo = searchParameters.get('repo');
@@ -265,6 +284,41 @@ export async function loadOstEnv() {
   };
 }
 
+function addToggleSwitch(container, label, checked, onChange) {
+  const switchDiv = createTag('div', { class: 'spectrum-Switch' }, null, { parent: container });
+  const input = createTag('input', { type: 'checkbox', class: 'spectrum-Switch-input', id: 'gb-overlay-toggle' }, null, { parent: switchDiv });
+  createTag('span', { class: 'spectrum-Switch-switch' }, null, { parent: switchDiv });
+  createTag('label', { class: 'spectrum-Switch-label', for: 'gb-overlay-toggle' }, label, { parent: switchDiv });
+  input.checked = checked;
+  input.addEventListener('change', onChange);
+  return input;
+}
+
+export function addToggleSwitches(el, ostEnv, masDefEnabled, windowObj) {
+  const { base } = getConfig();
+  loadStyle(`${base}/blocks/graybox/switch.css`);
+  const toggleContainer = createTag('span', { class: 'toggle-switch' }, null, { parent: el });
+  const inputLandscape = addToggleSwitch(toggleContainer, 'Draft landscape offer', ostEnv.landscape === WCS_LANDSCAPE_DRAFT, (e) => {
+    const url = new URL(window.location.href);
+    if (e.target.checked) {
+      url.searchParams.set(LANDSCAPE_URL_PARAM, WCS_LANDSCAPE_DRAFT);
+    } else {
+      url.searchParams.delete(LANDSCAPE_URL_PARAM);
+    }
+    windowObj.location.href = url.toString();
+  });
+  const inputDefaults = addToggleSwitch(toggleContainer, 'MAS defaults', masDefEnabled, (e) => {
+    const url = new URL(window.location.href);
+    if (!e.target.checked) {
+      url.searchParams.set(DEFAULTS_URL_PARAM, 'off');
+    } else {
+      url.searchParams.delete(DEFAULTS_URL_PARAM);
+    }
+    windowObj.location.href = url.toString();
+  });
+  return [inputLandscape, inputDefaults];
+}
+
 export default async function init(el) {
   el.innerHTML = '<div />';
 
@@ -281,6 +335,7 @@ export default async function init(el) {
       ...ostEnv,
       rootElement: el.firstElementChild,
     });
+    addToggleSwitches(el, ostEnv, masDefaultsEnabled, window);
   }
 
   if (ostEnv.aosAccessToken) {
diff --git a/test/blocks/ost/ost.test.html.js b/test/blocks/ost/ost.test.html.js
index cfe743f9d81..bd87e0da727 100644
--- a/test/blocks/ost/ost.test.html.js
+++ b/test/blocks/ost/ost.test.html.js
@@ -1,7 +1,7 @@
 import { expect } from '@esm-bundle/chai';
-
+import { delay } from '../../helpers/waitfor.js';
 import { mockOstDeps, unmockOstDeps } from './mocks/ost-utils.js';
-import { DEFAULT_CTA_TEXT, createLinkMarkup } from '../../../libs/blocks/ost/ost.js';
+import { DEFAULT_CTA_TEXT, createLinkMarkup, addToggleSwitches } from '../../../libs/blocks/ost/ost.js';
 
 const perpM2M = {
   offer_id: 'aeb0bf53517d46e89a1b039f859cf573',
@@ -306,3 +306,89 @@ describe('OST: merch link creation', () => {
     });
   });
 });
+describe('OST: toggle switches', () => {
+  it('change toggle switch landscape from PUBLISHED to DRAFT', async () => {
+    const el = document.createElement('div');
+    const ostEnv = { landscape: 'PUBLISHED' };
+    const windowObj = { location: {} };
+    const cbs = addToggleSwitches(el, ostEnv, true, windowObj);
+    const cbLandscape = cbs[0];
+    const cbLDefaults = cbs[1];
+
+    expect(cbLandscape.checked).to.be.false;
+    expect(cbLDefaults.checked).to.be.true;
+
+    cbLandscape.checked = true;
+    cbLandscape.dispatchEvent(new Event('change'));
+    await delay(100);
+
+    const url = new URL(windowObj.location.href);
+    expect(url.searchParams.get('commerce.landscape')).to.equal('DRAFT');
+    expect(url.searchParams.get('commerce.defaults')).to.be.null;
+  });
+  it('change toggle switch defaults on to off', async () => {
+    const el = document.createElement('div');
+    const ostEnv = { landscape: 'PUBLISHED' };
+    const windowObj = { location: {} };
+    const cbs = addToggleSwitches(el, ostEnv, true, windowObj);
+    const cbLandscape = cbs[0];
+    const cbLDefaults = cbs[1];
+
+    expect(cbLandscape.checked).to.be.false;
+    expect(cbLDefaults.checked).to.be.true;
+
+    cbLDefaults.checked = false;
+    cbLDefaults.dispatchEvent(new Event('change'));
+    await delay(100);
+
+    const url = new URL(windowObj.location.href);
+    expect(url.searchParams.get('commerce.landscape')).to.be.null;
+    expect(url.searchParams.get('commerce.defaults')).to.equal('off');
+  });
+  it('change toggle switch landscape from DRAFT to PUBLISHED', async () => {
+    const originalSearch = window.location.search;
+    window.history.replaceState({}, null, `${window.location.pathname}?commerce.landscape=DRAFT&commerce.defaults=off`);
+    const el = document.createElement('div');
+    const ostEnv = { landscape: 'DRAFT' };
+    const windowObj = { location: {} };
+    const cbs = addToggleSwitches(el, ostEnv, false, windowObj);
+    const cbLandscape = cbs[0];
+    const cbLDefaults = cbs[1];
+
+    expect(cbLandscape.checked).to.be.true;
+    expect(cbLDefaults.checked).to.be.false;
+
+    cbLandscape.checked = false;
+    cbLandscape.dispatchEvent(new Event('change'));
+    await delay(100);
+
+    const url = new URL(windowObj.location.href);
+    expect(url.searchParams.get('commerce.landscape')).to.be.null;
+    expect(url.searchParams.get('commerce.defaults')).to.equal('off');
+
+    window.history.replaceState({}, null, `${window.location.pathname}${originalSearch}`);
+  });
+  it('change toggle switch defaults off to on', async () => {
+    const originalSearch = window.location.search;
+    window.history.replaceState({}, null, `${window.location.pathname}?commerce.landscape=DRAFT&commerce.defaults=off`);
+    const el = document.createElement('div');
+    const ostEnv = { landscape: 'DRAFT' };
+    const windowObj = { location: {} };
+    const cbs = addToggleSwitches(el, ostEnv, false, windowObj);
+    const cbLandscape = cbs[0];
+    const cbLDefaults = cbs[1];
+
+    expect(cbLandscape.checked).to.be.true;
+    expect(cbLDefaults.checked).to.be.false;
+
+    cbLDefaults.checked = true;
+    cbLDefaults.dispatchEvent(new Event('change'));
+    await delay(100);
+
+    const url = new URL(windowObj.location.href);
+    expect(url.searchParams.get('commerce.landscape')).to.equal('DRAFT');
+    expect(url.searchParams.get('commerce.defaults')).to.be.null;
+
+    window.history.replaceState({}, null, `${window.location.pathname}${originalSearch}`);
+  });
+});