I strongly suggest that only stable builds be considered for usage in this flagship instance.
In case of Firefish, making the flagship instance a sandbox was not a good decision. Also, the major database update did not live up to the expectations as timelines still continue to feel buggier.
Though not dead, since Firefish is not fast enough in fixing issues that affect real users and real admins, I see that some Firefish instances are migrating to Sharkey or Iceshrimp.
Otherwise, for the most part, usage of Firefish has been a nice experience.
From a user perspective, both Sharkey and Iceshrimp have good prospects.