diff --git a/packages/fxa-content-server/app/scripts/lib/app-start.js b/packages/fxa-content-server/app/scripts/lib/app-start.js
index 10e13d4ad9..19991fe9ef 100644
--- a/packages/fxa-content-server/app/scripts/lib/app-start.js
+++ b/packages/fxa-content-server/app/scripts/lib/app-start.js
@@ -98,6 +98,7 @@ Start.prototype = {
     this._experimentGroupingRules = new ExperimentGroupingRules({
       env: this._config.env,
       featureFlags: this._config.featureFlags,
+      rolloutRates: this._config.rolloutRates,
     });
   },
 
diff --git a/packages/fxa-content-server/app/scripts/lib/experiment.js b/packages/fxa-content-server/app/scripts/lib/experiment.js
index 6cf92dac0b..9348020526 100644
--- a/packages/fxa-content-server/app/scripts/lib/experiment.js
+++ b/packages/fxa-content-server/app/scripts/lib/experiment.js
@@ -15,6 +15,7 @@ const UA_OVERRIDE = 'FxATester';
  */
 const STARTUP_EXPERIMENTS = {
   generalizedReactApp: BaseExperiment,
+  keyStretchV2: BaseExperiment,
 };
 
 /**
diff --git a/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/index.js b/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/index.js
index eabfac5e63..518050c905 100644
--- a/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/index.js
+++ b/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/index.js
@@ -25,6 +25,18 @@ class ExperimentChoiceIndex {
     this._experimentGroupingRules =
       options.experimentGroupingRules || experimentGroupingRules;
     this._featureFlags = options.featureFlags;
+
+    // Apply configured rollout rates
+    if (options.rolloutRates) {
+      for (const rule of this._experimentGroupingRules) {
+        if (typeof rule.setRolloutRate === 'function') {
+          const rate = options.rolloutRates[rule.name];
+          if (typeof rate === 'number') {
+            rule.setRolloutRate(rate);
+          }
+        }
+      }
+    }
   }
 
   /**
diff --git a/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/key-stretch.js b/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/key-stretch.js
index aa8d609023..56405659b9 100644
--- a/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/key-stretch.js
+++ b/packages/fxa-content-server/app/scripts/lib/experiments/grouping-rules/key-stretch.js
@@ -6,19 +6,20 @@
 
 const BaseGroupingRule = require('./base');
 
-const GROUPS = [
-  'control',
-  'v2',
-];
+const GROUPS = ['control', 'v2'];
 
-const ROLLOUT_RATE = 0.0;
+const DEFAULT_ROLLOUT_RATE = 0.0;
 
 module.exports = class KeyStretchGroupingRule extends BaseGroupingRule {
   constructor() {
     super();
-    this.name = 'key-stretch';
+    this.name = 'keyStretchV2';
     this.groups = GROUPS;
-    this.rolloutRate = ROLLOUT_RATE;
+    this.rolloutRate = DEFAULT_ROLLOUT_RATE;
+  }
+
+  setRolloutRate(rate) {
+    this.rolloutRate = rate;
   }
 
   /**
diff --git a/packages/fxa-content-server/app/scripts/lib/fxa-client.js b/packages/fxa-content-server/app/scripts/lib/fxa-client.js
index 834a5fcfae..9bfbf6570b 100644
--- a/packages/fxa-content-server/app/scripts/lib/fxa-client.js
+++ b/packages/fxa-content-server/app/scripts/lib/fxa-client.js
@@ -139,7 +139,7 @@ function determineKeyStretchVersion() {
   if (params.get('stretch') === '2') {
     return 2;
   }
-  if (ExperimentMixin.isInExperimentGroup('key-stretch', 'v2')) {
+  if (ExperimentMixin.isInExperimentGroup('keyStretchV2', 'v2')) {
     return 2;
   }
 
diff --git a/packages/fxa-content-server/app/scripts/lib/key-stretch-experiment-mixin.js b/packages/fxa-content-server/app/scripts/lib/key-stretch-experiment-mixin.js
index 1ad5fac601..63fb089853 100644
--- a/packages/fxa-content-server/app/scripts/lib/key-stretch-experiment-mixin.js
+++ b/packages/fxa-content-server/app/scripts/lib/key-stretch-experiment-mixin.js
@@ -8,9 +8,7 @@
    dependsOn: [ExperimentMixin],
 
    isInKeyStretchExperiment() {
-     const experimentGroup = this.getAndReportExperimentGroup(
-       'key-stretch'
-     );
+     const experimentGroup = this.getAndReportExperimentGroup('keyStretchV2');
      return experimentGroup === 'v2';
    },
  };
diff --git a/packages/fxa-content-server/app/tests/spec/lib/experiments/grouping-rules/key-stretch.js b/packages/fxa-content-server/app/tests/spec/lib/experiments/grouping-rules/key-stretch.js
index d562c79204..52afa20f00 100644
--- a/packages/fxa-content-server/app/tests/spec/lib/experiments/grouping-rules/key-stretch.js
+++ b/packages/fxa-content-server/app/tests/spec/lib/experiments/grouping-rules/key-stretch.js
@@ -3,9 +3,9 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
  import { assert } from 'chai';
- import Experiment from 'lib/experiments/grouping-rules/key-stretch-v2';
+ import Experiment from 'lib/experiments/grouping-rules/key-stretch';
 
- describe('lib/experiments/grouping-rules/key-stretch-v2', () => {
+ describe('lib/experiments/grouping-rules/key-stretch', () => {
    let experiment;
 
    beforeEach(() => {
@@ -36,13 +36,13 @@
      });
 
      it('returns true if rollout 100%', () => {
-      experiment.rolloutRate = 1.0;
-      assert.isTrue(
-        experiment.choose({
-          experimentGroupingRules: { choose: () => experiment.name },
-          uniqueUserId: 'user-id',
-        })
-      );
-    });
+       experiment.rolloutRate = 1.0;
+       assert.isTrue(
+         experiment.choose({
+           experimentGroupingRules: { choose: () => experiment.name },
+           uniqueUserId: 'user-id',
+         })
+       );
+     });
    });
  });
diff --git a/packages/fxa-content-server/server/lib/beta-settings.js b/packages/fxa-content-server/server/lib/beta-settings.js
index 8bc45e4b36..1a91b974fe 100644
--- a/packages/fxa-content-server/server/lib/beta-settings.js
+++ b/packages/fxa-content-server/server/lib/beta-settings.js
@@ -81,6 +81,12 @@ const settingsConfig = {
     signUpRoutes: config.get('showReactApp.signUpRoutes'),
     signInRoutes: config.get('showReactApp.signInRoutes'),
   },
+  rolloutRates: {
+    keyStretchV2: config.get('rolloutRates.keyStretchV2'),
+  },
+  featureFlags: {
+    keyStretchV2: config.get('featureFlags.keyStretchV2'),
+  },
 };
 
 // Inject Beta Settings meta content
diff --git a/packages/fxa-content-server/server/lib/configuration.js b/packages/fxa-content-server/server/lib/configuration.js
index cfa391caea..77f8abd361 100644
--- a/packages/fxa-content-server/server/lib/configuration.js
+++ b/packages/fxa-content-server/server/lib/configuration.js
@@ -220,6 +220,12 @@ const conf = (module.exports = convict({
       format: Boolean,
       env: 'FEATURE_FLAGS_FXA_STATUS_ON_SETTINGS',
     },
+    keyStretchV2: {
+      default: true,
+      doc: 'Enables V2 key stretching',
+      format: Boolean,
+      env: 'FEATURE_FLAGS_KEY_STRETCH_V2',
+    },
   },
   showReactApp: {
     simpleRoutes: {
@@ -789,6 +795,14 @@ const conf = (module.exports = convict({
     env: 'WEBPACK_MODE_OVERRIDE',
     format: String,
   },
+  rolloutRates: {
+    keyStretchV2: {
+      default: 0,
+      doc: 'The rollout rate for key stretching changes. Valid values are from 0 to 1.0',
+      env: 'ROLLOUT_KEY_STRETCH_V2',
+      format: Number,
+    },
+  },
   statsd: {
     enabled: {
       doc: 'Enable StatsD',
diff --git a/packages/fxa-content-server/server/lib/routes/get-index.js b/packages/fxa-content-server/server/lib/routes/get-index.js
index 1f11c7b6a0..71e4de64d3 100644
--- a/packages/fxa-content-server/server/lib/routes/get-index.js
+++ b/packages/fxa-content-server/server/lib/routes/get-index.js
@@ -59,6 +59,9 @@ module.exports = function (config) {
   const GLEAN_LOG_PINGS = config.get('glean.logPings');
   const GLEAN_DEBUG_VIEW_TAG = config.get('glean.debugViewTag');
 
+  // Rather than relay all rollout rates, hand pick the ones that are applicable
+  const ROLLOUT_RATES = config.get('rolloutRates');
+
   // Note that this list is only enforced for clients that use login_hint/email
   // with prompt=none. id_token_hint clients are not subject to this check.
   const PROMPT_NONE_ENABLED_CLIENT_IDS = new Set(
@@ -89,6 +92,7 @@ module.exports = function (config) {
     profileUrl: PROFILE_SERVER_URL,
     release: RELEASE,
     redirectAllowlist: REDIRECT_CHECK_ALLOW_LIST,
+    rolloutRates: ROLLOUT_RATES,
     scopedKeysEnabled: SCOPED_KEYS_ENABLED,
     scopedKeysValidation: SCOPED_KEYS_VALIDATION,
     sentry: {
diff --git a/packages/fxa-settings/src/lib/config.ts b/packages/fxa-settings/src/lib/config.ts
index cc329ee6d4..b5b1ea03d9 100644
--- a/packages/fxa-settings/src/lib/config.ts
+++ b/packages/fxa-settings/src/lib/config.ts
@@ -82,6 +82,12 @@ export interface Config {
     signUpRoutes: boolean;
     signInRoutes: boolean;
   };
+  rolloutRates?: {
+    keyStretchV2?: number;
+  };
+  featureFlags?: {
+    keyStretchV2?: boolean;
+  };
 }
 
 export function getDefault() {
diff --git a/packages/fxa-settings/src/models/contexts/AppContext.ts b/packages/fxa-settings/src/models/contexts/AppContext.ts
index f166d300fb..cc1d2c56de 100644
--- a/packages/fxa-settings/src/models/contexts/AppContext.ts
+++ b/packages/fxa-settings/src/models/contexts/AppContext.ts
@@ -38,7 +38,7 @@ export function initializeAppContext() {
     new UrlQueryData(new ReachRouterWindow())
   );
   const authClient = new AuthClient(config.servers.auth.url, {
-    keyStretchVersion: keyStretchExperiment.isV2() ? 2 : 1
+    keyStretchVersion: keyStretchExperiment.isV2(config) ? 2 : 1,
   });
   const apolloClient = createApolloClient(config.servers.gql.url);
   const account = new Account(authClient, apolloClient);
diff --git a/packages/fxa-settings/src/models/experiments/key-stretch-experiment.test.ts b/packages/fxa-settings/src/models/experiments/key-stretch-experiment.test.ts
new file mode 100644
index 0000000000..4d58d1fc70
--- /dev/null
+++ b/packages/fxa-settings/src/models/experiments/key-stretch-experiment.test.ts
@@ -0,0 +1,64 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { GenericData } from '../../lib/model-data';
+import { ReachRouterWindow } from '../../lib/window';
+import { KeyStretchExperiment } from './key-stretch-experiment';
+
+describe('Key Stretch Experiment Model', function () {
+  const ffOn = {
+    featureFlags: {
+      keyStretchV2: true,
+    },
+  };
+
+  const ffOff = {
+    featureFlags: {
+      keyStretchV2: false,
+    },
+  };
+
+  const window = new ReachRouterWindow();
+  let model: KeyStretchExperiment;
+  beforeEach(function () {
+    model = new KeyStretchExperiment(new GenericData({}));
+  });
+
+  afterEach(() => {
+    window.localStorage.removeItem(`__fxa_storage.experiment.keyStretchV2`);
+  });
+
+  it('is disabled by default', () => {
+    const model = new KeyStretchExperiment(new GenericData({}));
+    expect(model.isV2(ffOn)).toBeFalsy();
+    expect(model.isV2(ffOff)).toBeFalsy();
+  });
+
+  it('enables with stretch query parameter', () => {
+    const model = new KeyStretchExperiment(new GenericData({ stretch: '2' }));
+    expect(model.isV2(ffOn)).toBeTruthy();
+    expect(model.isV2(ffOff)).toBeFalsy();
+  });
+
+  it('enables with force experiment query parameters', () => {
+    const model = new KeyStretchExperiment(
+      new GenericData({
+        forceExperiment: 'keyStretchV2',
+        forceExperimentGroup: 'v2',
+      })
+    );
+    expect(model.isV2(ffOn)).toBeTruthy();
+    expect(model.isV2(ffOff)).toBeFalsy();
+  });
+
+  it('enables with content-server experiment', () => {
+    window.localStorage.setItem(
+      `__fxa_storage.experiment.keyStretchV2`,
+      JSON.stringify(JSON.stringify({ enrolled: true }))
+    );
+    const model = new KeyStretchExperiment(new GenericData({}));
+    expect(model.isV2(ffOn)).toBeTruthy();
+    expect(model.isV2(ffOff)).toBeFalsy();
+  });
+});
diff --git a/packages/fxa-settings/src/models/experiments/key-stretch-experiment.ts b/packages/fxa-settings/src/models/experiments/key-stretch-experiment.ts
index 8d151199b0..8d6bfdae88 100644
--- a/packages/fxa-settings/src/models/experiments/key-stretch-experiment.ts
+++ b/packages/fxa-settings/src/models/experiments/key-stretch-experiment.ts
@@ -4,6 +4,7 @@
 
 import { IsOptional, IsString } from 'class-validator';
 import { bind, ModelDataProvider } from '../../lib/model-data';
+import * as Sentry from '@sentry/browser';
 
 export class KeyStretchExperiment extends ModelDataProvider {
   @IsOptional()
@@ -21,11 +22,68 @@ export class KeyStretchExperiment extends ModelDataProvider {
   @bind()
   forceExperimentGroup?: string;
 
-  isV2() {
-    return (
-      this.stretch === '2' ||
-      (this.forceExperiment === 'key-stretch' &&
-        this.forceExperimentGroup === 'v2')
-    );
+  isV2(config: { featureFlags?: { keyStretchV2?: boolean } }) {
+    // If the feature flag is off or unspecified, always disable the functionality!
+    if (!config.featureFlags?.keyStretchV2) {
+      return false;
+    }
+
+    // If stretch=2 in the URL, then force V2 key stretching for this page render,
+    // This is used for dev/test purposes.
+    if (this.stretch === '2') {
+      return true;
+    }
+
+    // If force experiment params are in URL, then force V2 key stretching, and
+    // automatically enroll in experiment, so that content server will pick it up.
+    if (
+      this.forceExperiment === 'keyStretchV2' &&
+      this.forceExperimentGroup === 'v2'
+    ) {
+      enrollInExp('keyStretchV2', true);
+      return true;
+    }
+
+    if (isEnrolledIn('keyStretchV2')) {
+      return true;
+    }
+
+    // Typical state. Not enrolled and not using V2 key stretching.
+    return false;
+  }
+}
+
+/**
+ * Sets state for a local experiment. Typically this is set by
+ * content-server/backbone, but we are in the midst of a migration to
+ * react. So for now we will sort of go behind the content server's back
+ * here. Note, that this will only happen if force experiment query params
+ * are set. Otherwise, the experiment will not be activated, or have to be
+ * activated by a content server / backbone page.
+ */
+function enrollInExp(key: string, enrolled: boolean) {
+  window.localStorage.setItem(
+    `__fxa_storage.experiment.${key}`,
+    JSON.stringify(JSON.stringify({ enrolled }))
+  );
+}
+
+/**
+ * Check if local storage indicates an active key stretch experiment.
+ * This is set by content-server/backbone. In the future we will be
+ * porting over experimentation code into settings, but this is in flux
+ * at the moment. See FXA-9183 for more info and latest status
+ */
+function isEnrolledIn(key: string) {
+  try {
+    let value: any = window.localStorage.getItem(
+      `__fxa_storage.experiment.${key}`
+    );
+    const json = value ? JSON.parse(JSON.parse(value)) : { enrolled: false };
+    return json.enrolled === true;
+  } catch (error) {
+    Sentry.captureException(error);
+    // If value was malformed then assume false.
+    return false;
   }
 }
diff --git a/packages/fxa-settings/src/pages/ResetPassword/CompleteResetPassword/index.tsx b/packages/fxa-settings/src/pages/ResetPassword/CompleteResetPassword/index.tsx
index b50996f10e..f743f7a80e 100644
--- a/packages/fxa-settings/src/pages/ResetPassword/CompleteResetPassword/index.tsx
+++ b/packages/fxa-settings/src/pages/ResetPassword/CompleteResetPassword/index.tsx
@@ -15,6 +15,7 @@ import {
   useFtlMsgResolver,
   isSyncDesktopV3Integration,
   isSyncOAuthIntegration,
+  useConfig,
 } from '../../../models';
 import WarningMessage from '../../../components/WarningMessage';
 import LinkRememberPassword from '../../../components/LinkRememberPassword';
@@ -71,6 +72,7 @@ const CompleteResetPassword = ({
   const navigate = useNavigate();
   const navigateWithoutRerender = useNavigateWithoutRerender();
   const keyStretchExperiment = useValidatedQueryParams(KeyStretchExperiment);
+  const config = useConfig();
   const account = useAccount();
   const location = useLocation() as ReturnType<typeof useLocation> & {
     state: CompleteResetPasswordLocationState;
@@ -217,7 +219,7 @@ const CompleteResetPassword = ({
         GleanMetrics.resetPassword.createNewSubmit();
 
         const accountResetData = await account.completeResetPassword(
-          keyStretchExperiment.queryParamModel.isV2(),
+          keyStretchExperiment.queryParamModel.isV2(config),
           token,
           code,
           emailToUse,
@@ -268,6 +270,7 @@ const CompleteResetPassword = ({
       ftlMsgResolver,
       setLinkStatus,
       keyStretchExperiment,
+      config,
     ]
   );
 
diff --git a/packages/fxa-settings/src/pages/Signin/container.tsx b/packages/fxa-settings/src/pages/Signin/container.tsx
index 434dde6487..2e4ad8a5f6 100644
--- a/packages/fxa-settings/src/pages/Signin/container.tsx
+++ b/packages/fxa-settings/src/pages/Signin/container.tsx
@@ -9,6 +9,7 @@ import {
   isSyncDesktopV3Integration,
   useAuthClient,
   useFtlMsgResolver,
+  useConfig,
 } from '../../models';
 import { MozServices } from '../../lib/types';
 import { useValidatedQueryParams } from '../../lib/hooks/useValidate';
@@ -82,6 +83,7 @@ const SigninContainer = ({
   integration: SigninContainerIntegration;
   serviceName: MozServices;
 } & RouteComponentProps) => {
+  const config = useConfig();
   const authClient = useAuthClient();
   const ftlMsgResolver = useFtlMsgResolver();
   const navigate = useNavigate();
@@ -205,7 +207,7 @@ const SigninContainer = ({
       const v1Credentials = await getCredentials(email, password);
       let v2Credentials = null;
 
-      if (keyStretchExp.queryParamModel.isV2()) {
+      if (keyStretchExp.queryParamModel.isV2(config)) {
         const credentialStatusData = await credentialStatus({
           variables: {
             input: email,
@@ -355,6 +357,7 @@ const SigninContainer = ({
       keyStretchExp.queryParamModel,
       passwordChangeFinish,
       passwordChangeStart,
+      config,
     ]
   );
 
diff --git a/packages/fxa-settings/src/pages/Signup/container.tsx b/packages/fxa-settings/src/pages/Signup/container.tsx
index 70f05ba6bd..43709bca46 100644
--- a/packages/fxa-settings/src/pages/Signup/container.tsx
+++ b/packages/fxa-settings/src/pages/Signup/container.tsx
@@ -205,7 +205,7 @@ const SignupContainer = ({
         // If enabled, add in V2 key stretching support
         let credentialsV2 = undefined;
         let passwordV2 = undefined;
-        if (keyStretchExp.queryParamModel.isV2()) {
+        if (keyStretchExp.queryParamModel.isV2(config)) {
           credentialsV2 = await getCredentialsV2({
             password,
             clientSalt: await createSaltV2(),
@@ -258,7 +258,7 @@ const SignupContainer = ({
         return handleGQLError(error);
       }
     },
-    [beginSignup, integration, isSyncDesktopV3, isOAuth, keyStretchExp]
+    [beginSignup, integration, isSyncDesktopV3, isOAuth, keyStretchExp, config]
   );
 
   // TODO: probably a better way to read this?