This isn't going to be the answer you're actually looking for, but it may be enough to tide you over until you find a solution.
It's a little tiny app that will turn a windowed application into a "fullscreen borderless windowed" application. Works amazing for OOTP. I run multi-monitor and it lets me have OOTP running "fullscreen", while still being able to use the browser on the 2nd monitor without OOTP minimizing to task switch.
https://github.com/KasumiL5x/Fullscreenizer
As they say, proof is in the pudding...