I run Rhino full screen on my secondary monitor and GH full screen on my primary, and I switch back and forth between them fairly frequently.
I’ve had only 2 problems with this, and one is my fault: both Rhino and GH will respond to the keyboard only if their window has the current focus, and this means I have to click on something when I move the cursor from one screen to the other. What I frequently do is switch my mental focus from one screen to the other (without clicking on something) and then turn my scroll wheel - which of course scrolls or zooms the “wrong” screen.
The other problem is that after Baking something and giving Rhino the focus, the delete key
sometimes does nothing. But using the Rhino menus to delete does work. This seems like a quirk to me, but I’m not really sure why it happens.