Hi @JFoxUK,
You are right that you cannot host a multi-step onboarding form directly within the Universal Login pages using ACUL, but that doesn’t mean you shouldn’t use the Post-Login Action approach. ACUL is designed to customize the identity pages (Login, Reset Password, MFA), not to build custom business workflows or multi-page data collection forms.
The recommended path is the Redirect Action. Host a simple, lightweight page that matches your ACUL extra data collecting page, and you should be good to go. Once the user hits “Submit” on your page, you redirect them back to the Auth0 /continue endpoint with the signed session token.
Have a good one,
Vlad