diff --git a/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.test.tsx b/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.test.tsx
index 70dac621b..6ebb38125 100644
--- a/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.test.tsx
+++ b/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.test.tsx
@@ -234,6 +234,7 @@ describe("ProjectOnboardingWizard", () => {
       throw new Error("Stripe account info should not load on the app selection step.");
     });
     const listEmailThemes = vi.fn(async () => []);
+    const getEmailPreview = vi.fn(async () => "");
     const getStripeAccountInfo = vi.fn(async () => null);
 
     render(
@@ -265,6 +266,7 @@ describe("ProjectOnboardingWizard", () => {
           app: {
             setupPayments: vi.fn(async () => ({ url: "https://example.com" })),
             listEmailThemes,
+            getEmailPreview,
             getStripeAccountInfo,
             useEmailThemes,
             useStripeAccountInfo,
@@ -280,6 +282,7 @@ describe("ProjectOnboardingWizard", () => {
     );
 
     expect(listEmailThemes).toHaveBeenCalledOnce();
+    expect(getEmailPreview).not.toHaveBeenCalled();
     expect(getStripeAccountInfo).not.toHaveBeenCalled();
     expect(useEmailThemes).not.toHaveBeenCalled();
     expect(useStripeAccountInfo).not.toHaveBeenCalled();
diff --git a/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.tsx b/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.tsx
index 929adf18c..e50b27414 100644
--- a/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.tsx
+++ b/apps/dashboard/src/app/(main)/(protected)/(outside-dashboard)/new-project/page-client-parts/project-onboarding-wizard.tsx
@@ -33,6 +33,7 @@ import {
 import { AuthPage, type AdminOwnedProject } from "@hexclave/next";
 import { type AppId } from "@hexclave/shared/dist/apps/apps-config";
 import { type EnvironmentConfigOverrideOverride } from "@hexclave/shared/dist/config/schema";
+import { previewTemplateSource } from "@hexclave/shared/dist/helpers/emails";
 import { runAsynchronously, runAsynchronouslyWithAlert } from "@hexclave/shared/dist/utils/promises";
 import { Suspense, useCallback, useEffect, useMemo, useRef, useState } from "react";
 
@@ -187,7 +188,10 @@ export function ProjectOnboardingWizard(props: {
     }
 
     runAsynchronously(async () => {
-      await project.app.listEmailThemes();
+      const themes = await project.app.listEmailThemes();
+      await Promise.allSettled(themes.map((theme) =>
+        project.app.getEmailPreview({ themeId: theme.id, templateTsxSource: previewTemplateSource })
+      ));
     }, { noErrorLogging: true });
   }, [isLinkExistingMode, project.app, status]);
 
diff --git a/packages/template/src/lib/hexclave-app/apps/implementations/admin-app-impl.ts b/packages/template/src/lib/hexclave-app/apps/implementations/admin-app-impl.ts
index e8fe88bc9..6234d69bd 100644
--- a/packages/template/src/lib/hexclave-app/apps/implementations/admin-app-impl.ts
+++ b/packages/template/src/lib/hexclave-app/apps/implementations/admin-app-impl.ts
@@ -828,7 +828,8 @@ export class _HexclaveAdminAppImplIncomplete<HasTokenStore extends boolean, Proj
   }
 
   async getEmailPreview(options: { themeId?: string | null | false, themeTsxSource?: string, templateId?: string, templateTsxSource?: string }): Promise<string> {
-    return (await this._interface.renderEmailPreview(options)).html;
+    const result = Result.orThrow(await this._emailPreviewCache.getOrWait([options.themeId, options.themeTsxSource, options.templateId, options.templateTsxSource], "write-only"));
+    return result.html;
   }
   // IF_PLATFORM react-like
   useEmailPreview(options: { themeId?: string | null | false, themeTsxSource?: string, templateId?: string, templateTsxSource?: string }): string {