I had another streamer join the stream together but they weren't live but were joining as a guest, I could hear them and everything was going through fine but they were no longer able to see the stream content after joining and we couldn't figure out how to solve this bug. So perhaps the waiting room dashboard could also have a box for the currently being streamed content (of any streamer involved who is currently live) as options of sources, so anyone participating can view a stream if that is required for the content, but perhaps even be an additional option alongside the simple individual sources for each cam.

There is a chance that me choosing to have each guest as their own browser source makes it so the stream isn't visible as it doesn't have it's own source, but it did seem to be creating issues so my guest could no longer see the stream (during a jackbox stream where it would be essential for them to really see the screen as well as being in the call to participate)

Obviously having access to any currently live streamer's stream in the call also opens up additional options like having smaller boxes of the other streamers perspective in games also you could add in besides simply having their cam on so incorporating these would be a good feature request too.