I am using a two monitor setup, The TV for KODI and the other monitor for work and web browsing. I could use the two simultaneously via Kodi remote mobile app, Yatse.

I would like to have some games on the TV while be able to work or browse the web on the other monitor, again simultaneously.

Because of the Active window/Inactive window, the input for controller wouldn't work if someone would type on the keyboard or push a mouse button on other applications.
This 'supposed to be' a two terminal job, I have looked into multi seating, virtual machines and other solutions, they are not working for me.

I would suggest an additional option in CC's settings for the two or multiple monitors.
So you could assign CC to work with even inactive processes.

This would replace my Kodi solution and set free the TV for gaming.
The PC would have two usage at the same time. It would be amazing.

Since the inactive window would get the Controller input it would still work 'in the background', and the active processes would work as before. Since the window is inactive, it wouldn't get keyboard strokes or mouse movements but Controller commands exclusively.

It could get messy only when the game process would get active somehow (closing applications would make Windows to automatically switch to the next inactive window), but I think it is still worth to try.

Yes, this would need an additional overlay for choosing the right inactive application for CC to work with. And it would need to be displayed on both monitors, so there wouldn't be any confusion which one your operating with.
And I haven't even said anything about multiple controllers yet.

I would very much appreciate it if You could look into this, I think I'm not alone with this problem, and it could turn around gaming for me.

Thank you very much!