Keynote Play presentation on 1 display and Just see my desktop on my second
This issue has been bugging me for ages. However, Apple has finally updated Keynote, half-assed but still.
In Keynote 10.1, there is finally the Play &gt; Play Slideshow in Window option which does exactly that.
You'll have a window (where still the window bar shows up when you move the mouse, well done Apple!) with your presentation, you can resize it and move it wherever you want, share it with Zoom or another video conference tool and still be able to see your Desktop.