One thing that seems to go unappreciated in the comments is the simplicity of this interop proposal: It is essentially about enabling quote-posting of link-aggregator(Groups) posts.
Bluesky + Frontpage will work this way, and I believe it’ll work exceedingly well. If the ap-net corner of the fediverse isn’t interested in this kind of interop, fair enough. To me however the promise of seamless interop between my social apps was what brought me to the fediverse, so that’s the version of the fediverse I will pursue.