Add a small mini mode window that is always on top for muting sound and video, like the old RC Meetings application
When using the old RC Meeting application, you could minimize it to a mini mode window. If on a computer with only one screen, you could type in notes on one screen, and still be able to mute and unmute yourself on the mini allways-on-top RC Meetings window.
It had three buttons mute, start and stop video, and maximize. It also displayed who was currently talking.