LadybugDB (https://github.com/LadybugDB/ladybug) at this point seems to be the only sustainable fork. When deciding what to do about the Kuzu archival on https://gdotv.com, we've gone with maintaining support for the last available version of Kuzu (it's still heavily used from what I'm seeing) whilst introducing support for LadybugDB.
I've looked into a few other forks and at this point in time none seem to be actively maintained for more than a few weeks before getting dropped.