I would really like to see Spaces added if possible. This app is quite good and would be excellent to recommend seriously as a Discord alternative, with the mainline Element client being substantially slower and clunkier. Spaces support would deliver that.
I use them essentially like folders of chats, similar to discord having many rooms in one server, so I for example have a space for External Servers (I.e federated chats in other homeservers), a Personal space with chats only I can access, etc.