The change would be using Gitmail as the plumbing, and normalising the creation of user-friendly porcelain on top.

E.g. suppose there is a repo foo/bar hosted by a forgejo instance at myinstance.org/foo/bar. Sending an email to foo.bar@myinstance.org (or similar) could automatically create a PR and, conversely, opening a PR could send a patch series to the foo/bar mailing list.

To be honest, I’m starting to drink the Sourcehut coolaid here. We have a distributed method of interacting with repositories: Email.

Don’t get me wrong, the current user experience of email-based patches and discussion isn’t great because it’s too easy to send a badly formatted patch. But if we invested time in making email patches easier to use (e.g. sending them through a web ui for people who prefer github style PRs) then we could skip all the architectural pains of solutions like forgefed.