i'm glad that ActivityPub reached Recommendation status before the Working Group charter expired but I think
1. It needs a 1.1 or 2.0 release to clarify a LOT of behaviors and clean up a lot of aspects of the spec
2. That 1.1/2.0 draft should basically be a rewrite informed by how it is (a) being used, and (b) planned to be used by implementors in the wild, with special attention paid to implementations with unconventional needs