While I like our solution to group chats, after reflecting on more recent experience with Matrix, I think the ability to have separate rooms with the same set of participants is indispensible. Rather than revise our approach to groups, I propose we could just add a "topic" field on messages, similar to email, and have a view that splits conversations based on the combination of that and recipient list. I believe this is still simpler than having first-class "groups" or "rooms" in the protocol, and perhaps more flexible too.

But even if my proposal is agreed on, we would put this off until all other essentials are in place.