BlackSky seems to be run by a competent dev with a high enough profile that I see his posts regularly without following him directly
Based on his progress posts it seems that ATproto is intentionally moving in the right direction and BlackSky has progressed to the point he’s asking for volunteers to move off Bluesky and try out his implementations
https://www.blackskyweb.xyz - it's the black people community on Bluesky, they started first with some custom feeds and blocklists/labeller, now they have a PDS and relay, and they're planning to launch a forked version of the app and eventually have a full independent infra basically. With some extra features like option to make "internal" posts that aren't shared with the wider Bluesky but only with people on the PDS.
What is this BlackSky you're talking about?