Onboarding of Brokered IDP logins

Hello all,
Looking for some guidance. I have an external identity provider setup for a realm. Want to create an onboarding/registration experience that goes like this:

  1. Authenticate via the external identity provider, required.
  2. Placed into a pending status until additional actions are completed. Something that prevents them from logging into any service providers. Post login group membership check, etc.
  3. Complete additional checks and setup of their account.
  4. Set password reset and possibly other actions on their account, i.e. review profile, configure otp, etc.
  5. Notify them when those additional actions are completed.

I have created a custom event filter spi that detects registration events. However, when I try to add an identity provider redirect into the registration auth flow it errors out. So, I don’t know if it possible to leverage the registration process. How would I go about detecting new accounts that are created during first broker logins? Is there an event type that detects that? Do I need to create a custom authenticator and add it to the authentication flow to initiate the additional steps (i.e. add them to a queue for processing) that I need to complete before I notify them that their account is ready to go?