Excuse my ignorance here. To what extent can this problem be simplified with DIDs or Decentralized IDs, rather than "federated accounts".
Take the example of Filpboard. I signed up to integrate #mastodon with #bluesky. Supposedly, they have AI to process two disparate systems. The result: Nada. Why? Because I have to put some verification HTML in a website.
I have a "domain name handle" that should allow two independent information sources to communicate. The same account, or DID, needs to work on both systems. I don't see that.