@frequency now fully supports FEP-7888 as of yesterday! (It has been generating outbound context since the beginning of the year, but I just finished fetching all remote replies from the context as well.)
https://github.com/jesseplusplus/decodon/pull/188
I'll hold off on trying to upstream this to Mastodon until after the 4.4.0 release to make sure I'm not conflicting with anything they changed.