diff --git a/.circleci/config.yml b/.circleci/config.yml
index 04ef5634826e..6db12bf41959 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -560,27 +560,27 @@ workflows:
           requires:
             - unit-tests
       - create-sandboxes:
-          parallelism: 23
+          parallelism: 21
           requires:
             - build
       - build-sandboxes:
-          parallelism: 23
+          parallelism: 21
           requires:
             - create-sandboxes
       - chromatic-sandboxes:
-          parallelism: 20
+          parallelism: 18
           requires:
             - build-sandboxes
       - e2e-production:
-          parallelism: 18
+          parallelism: 16
           requires:
             - build-sandboxes
       - e2e-dev:
-          parallelism: 4
+          parallelism: 2
           requires:
             - create-sandboxes
       - test-runner-production:
-          parallelism: 18
+          parallelism: 16
           requires:
             - build-sandboxes
       - bench:
@@ -614,30 +614,30 @@ workflows:
           requires:
             - build
       - create-sandboxes:
-          parallelism: 38
+          parallelism: 36
           requires:
             - build
       # - smoke-test-sandboxes: # disabled for now
       #     requires:
       #       - create-sandboxes
       - build-sandboxes:
-          parallelism: 38
+          parallelism: 36
           requires:
             - create-sandboxes
       - chromatic-sandboxes:
-          parallelism: 35
+          parallelism: 33
           requires:
             - build-sandboxes
       - e2e-production:
-          parallelism: 33
+          parallelism: 31
           requires:
             - build-sandboxes
       - e2e-dev:
-          parallelism: 4
+          parallelism: 2
           requires:
             - create-sandboxes
       - test-runner-production:
-          parallelism: 33
+          parallelism: 31
           requires:
             - build-sandboxes
       # TODO: reenable once we find out the source of flakyness
diff --git a/code/lib/cli/src/sandbox-templates.ts b/code/lib/cli/src/sandbox-templates.ts
index 55a4f428ddfa..b40bdb4f22f8 100644
--- a/code/lib/cli/src/sandbox-templates.ts
+++ b/code/lib/cli/src/sandbox-templates.ts
@@ -466,34 +466,6 @@ const baseTemplates = {
  * They will be hidden by default in the Storybook status page.
  */
 const internalTemplates = {
-  'internal/ssv6-vite': {
-    ...baseTemplates['react-vite/default-ts'],
-    name: 'StoryStore v6 (react-vite/default-ts)',
-    isInternal: true,
-    modifications: {
-      mainConfig: {
-        features: {
-          storyStoreV7: false,
-          storyStoreV7MdxErrors: false,
-        },
-      },
-    },
-    skipTasks: ['bench'],
-  },
-  'internal/ssv6-webpack': {
-    ...baseTemplates['cra/default-ts'],
-    name: 'StoryStore v6 (cra/default-ts)',
-    isInternal: true,
-    modifications: {
-      mainConfig: {
-        features: {
-          storyStoreV7: false,
-          storyStoreV7MdxErrors: false,
-        },
-      },
-    },
-    skipTasks: ['bench'],
-  },
   'internal/swc-webpack': {
     ...baseTemplates['react-webpack/18-ts'],
     name: 'SWC (react-webpack/18-ts)',
@@ -615,8 +587,6 @@ export const merged: TemplateKey[] = [
   'preact-vite/default-ts',
   'html-webpack/default',
   'html-vite/default-ts',
-  'internal/ssv6-vite',
-  'internal/ssv6-webpack',
 ];
 export const daily: TemplateKey[] = [
   ...merged,
diff --git a/scripts/tasks/sandbox-parts.ts b/scripts/tasks/sandbox-parts.ts
index 45cc2039ef0c..2cb95acaf83c 100644
--- a/scripts/tasks/sandbox-parts.ts
+++ b/scripts/tasks/sandbox-parts.ts
@@ -100,7 +100,6 @@ export const install: Task['run'] = async ({ sandboxDir }, { link, dryRun, debug
         'bench-react-vite-default-ts',
         'bench-react-vite-default-ts-nodocs',
         'bench-react-vite-default-ts-test-build',
-        'internal-ssv6-vite',
         'react-vite-default-js',
         'react-vite-default-ts',
         'svelte-vite-default-js',