I stole a few ideas from did:plc and did:tdw, yes. It's just an experiment insofar, as I'm using it as a stand-in for other methods, as something I can adjust to my needs as I toy with DIDs in a way with reverse-compatibility to standard non-DID ActivityPub.
As it currently stands, there doesn't seem to be a lot of methods that clarify whether DID URLs are permitted or not with the method.
There were a few adjustments I was going to add, such as what other 'authoritative' servers the did:fedi can be discovered from, within the method-specific protocol, maybe.
Either way, I haven't been public about it yet. Just finished a basic key wrapping and serialization format to go along with it, and I'll probably push out a newer version of the generator demo (which presently lacks a polyfill for browsers that don't have native Ed25519 within WebCrypto) in a day or two. I'll probably be more vocal when I have results.
As for the primer, that was probably over a year ago, and the mentioned FEPs, even a year before that (with all those FEPs devised by @silverpill )