I’m skipping over Authelia. Social federation is important for me because I do not want to deal with password (see also the WebAuthN bit). Last thing I want is trying to maintain and keep up-to-date a separate service that’s supposed to keep my other services secure, but becoming a single point of failure for my password(s) (so same goes with no self hosting password manager).
Do you mind touching on the integration issues you mentioned? What was the problem, and what were the side effect as result of it?