One concern I would have with this is secrets handling. Say I'm screen sharing my development environment and I come across a secret, I would want my screen share service to be able to detect a secret is on screen and to either block it out or just cut off the screen share entirely until it is no longer on screen. This likely isn't foolproof, so having a hotkey to pause/unpause screen share when I know I'm about to deal with secrets would be useful as well.

That's a good idea. Of course, sharing your screen at all would be optional in the "Let's have some company while we're working on stuff" friendly circle of folks.