Sometimes I find myself missing conversations that I should be seeing because I wasn't added when the group was created.

It'd be really helpful if, periodically, Comms could send me a message along the lines of "people in groups similar to you also joined X, Y, and Z" and make it easy for me to join those groups.

If I'm not part of a group, I don't know what I don't know. This can be a useful feature for discoverability of information and it can increase "signal" for the signal-to-noise problem.