Registration Approvals & SSO - Possible to Moderate Registrations for some but not all?

We use our own SSO for logging-in and signing up for the community. We’re also exploring ways to open up our community. 

Is it possible to exclude some new registrations from requiring moderator approval? Or to trigger moderator approval for certain types of registrations? 

For our use case, here’s the ideal state: 

• User logs in with SSO & does not have an account → account registration page → auto-approved, no registration moderation
• User does not use SSO, clicks to create an account → account registration page → registration moderation required

I could imagine similar use cases for whitelisting / blacklisting user registration for other communities.