BTW I hope any project won’t increase the Z version only by including Dependabot commits, it would be insane. Release must be documented, tested, with CHANGELOG updated. If some maintainers just accept Dependabot commits without checking, move away. That’s just simple crappy auto-merge.

Nice idea 👍

Whatever the solution behind is, if you have the resources, move to something self-hosted. Open core or not, if that topic matters to you, you might need something you can own and control. BTW, have a look on Forgejo, Codeberg and Gitea: these are the solutions I see when people look for something FLOSS, not open core, and maybe self-hostable.

I would have said in fact Matrix or XMPP-based solutions but it seems you already have spotted them. Maybe Mattermost?