O365 adfs

[jon.leics]

In office 365 can I enable adfs authentication for just a specific group of users? Or can I have adfs configured for just IDP initiates authenicaion but also allow non adfs logins?

We are migrating to office 365 and want to integrate adfs in a staged approach

[#2]

You would need to have the pilot users log in using a different UPN from the rest of the users - see https://techcommunity.microsoft.com/t5/Identity-Authentication/Plan-to-Test-ADFS-SSO-with-Production...

[#3]

Federated identity is configured by domain. So you need to register another domain to Office 365 and change users' UPNs to use that domain.