I've created this chrome extension that allows me to hide Figma's UI in the prototype mode, so when I do user testing, they don't get confused because of that overlay appearing out of the blue when moving the mouse top/bottom.
I'm aware you can disable this by going full screen, but I don't like to test in full screen as I prefer the experience to be as real as possible.
Just wanted to share it in case you feel the same.
Here is a youtube video https://www.youtube.com/watch?v=rpDHIU0jAOY
And this is the link to the extension https://chrome.google.com/webstore/detail/figma-clean-prototypes/dllfomnenkbbgfifpmgmggpplpfkafin?authuser=0
(it's also my first extension ever)