MLS would appear to be a pretty fundamental building block there. MLS can be a bridge between Nostr, atproto, Farcaster and others, and MLS can really scale. Example of one of the many ongoing atproto MLS discussions:
Discussion
π― I think mls is going to be a really important part of this.
Have you, by any chance, seen anyone in the atproto space hint at ways to set up MLS groups for non-chat content types?
No. I know for a fact that they are discussing it but the ATProto architecture really doesnβt make it easy.
nostr:npub1wmr34t36fy03m8hvgl96zl3znndyzyaqhwmwdtshwmtkg03fetaqhjg240 probably knows more details.
Boris here a good follow for MLS updates on atproto.

Yeah, that's why I'd look there, if they found a way β it's gonna be easier here.
Still wrapping my head around how to group groups π.
Having all content types in one group isn't an option (limits we discussed).
And having "links" to other MLS groups (of the same group) in the nostr_group_data extension seems like a dumb idea.