Strypey (was at Quitter.se) is a user on mastodon.nzoss.nz. You can follow them or interact with them if you have an account anywhere in the fediverse.
If you don't, you can sign up here.
I wonder if a #fediverse social app is really what the #Mastodon exodus folks want at all? Maybe they'd be happier on an instance(s) of a platform like #Crabgrass or #Loomio? These are designed for membership-based groups that can selectively federate, or hold cross-group discussions, but only within an instance. Both are intended for group organizing and have decision-making tools baked-in.
Either way, I recommend one or the other of these (or #Discourse) as a governance discussion platform for any #PeerProduction community. #Social.coop uses #Loomio for this.