In windows 10, it was easy to find CPrivilegedPresentationOperations vtable address in code section but they changed it with Win11, now you need to search in memory but still doable and requires no hooking. With that vtable, you can get IAMKey (kinda unneccessary) and also you can just call 4th func which is SetWindowBand does all the job for you, if you want you can also hook WndProc to use sendmessage from another app with needed params in order to call it anytime you want, benefit of doing this is WndProc runs on GUI thread which has an IAM thread.

Alternatively you can go kernelmode and it’s much more simpler, its after ExStyles2 just set it and works. I also tried setting ZBID_IMMERSIVE_RESTRICTED from kernel, it makes other windows crash

Я по китайски не шпрехаю.

Можно еще проинжектить dwm и перехватывать то, что он компонует, но я бы забил.