@dansup @mario FEP-5624 is not my proposal, it was submitted by Mastodon devs (they are present on SocialHub but not very active). I don't even like it, in my opinion Conversation Containers by @mikedev is better because it can be used for public and private groups too.
I'm participating in several AP / fedi matrix chats, but discussions there are less productive because of their ephemeral nature. Besides being good place for long thoughtful discussions, SocialHub also supports ActivityPub (beta, via Discourse plugin) so you can test interop between it and your groups implementation (if you support FEP-1b12).