Good luck detecting that with any kind of client-side anti-cheat.

The game will now only play on a “secure” display, and the anti-cheat has privileges to monitor the entire chain from the GPU to the display. Non-conforming monitors or devices in the middle break the chain of trust and the game refuses to play.

And then cheaters will shift to a camera pointed at the screen…

Client-side anti cheat is an endless cat-and-mouse game.