Switch window when sharing without joining meeting

I use Zoom Room. Sometimes I have to share something from my computer which is not joined to meeting. When I want to share screen, I have to enter Sharing Key (automatic detection does not work on Mac with external display). So far all good. The problem is when I want to switch window I want to share. I have to stop sharing existing window and start new share, which means I have to enter Sharing key again. It would be much better if I would have na option to switch window in existing share.

P.S. Sharing whole desktop is not an option.