Just another post to mention the issues with Steam Link and Remote Play, where the launcher hangs the stream.
This happens on some other launchers too & it's, as far as I can tell, because they're borderless windows at a lower resolution than the main desktop. A simple fix I'm pretty certain about would be to add an option to make it a normal window (with frame) or scale it up to the desktop resolution (as in borderless fullscreen). I understand that might not be desirable as the default, but having some way to do it would allow streaming again.
For anyone stuck, for the moment you can work around it by using Moonlight to stream things over & that doesn't share the Steam issue, but it's a lot less user friendly.