Thanks!

Maybe I wasn't too clear on the post about one thing, though. There is no need to fork the browser. I believe this could be implemented as a simple browser extension or even as Progressive Web App, like Voyager or Elk. The idea that I'm working with is actually to fork either one of these applications and just change its internal libraries to make it "speak" ActivityPub directly, instead of using Mastodon's or Lemmy's APIs.

Is there a discussion about this somewhere on the web?

Specifically about this approach, no. But https://matrix.to/#/#fediverse:pixie.town is a good room for people working in Fediverse/Social Web.