I was on firefish’s previous instance, known as calckey, before I migrated back to Mastodon.
There were definitely warning signs that the project was facing maintenance issues in those days as well, and it felt that the Firefish rebrand was an attempt to “start a new”.
But just like my post on KBin’s demise, it should be a warning to those who want to make the software and host a “big” instance: Don’t do it. I think it’s smart to host your own mini instance for testing, but you should probably solely focus on the code development side of things to make sure that you aren’t over burdening yourself with managerial tasks. If your software is good, people will make spins inevitably. If people use it, then you will probably have enough people contributing that you can scale up your mini-instance if needed. But don’t jump in without the finances in place, because you’re essentially taking on two jobs.