Earlier quoted context omitted.
> Games that rudely switch to fullscreen, I can run in Wine Virtual Desktop. Previously on Windows, I had to configure hacks like DxWnd and it didn't always work. Maybe Wine could be ported to Windows :-)
It already is in some form! This is what I used to play Sid Meier's Civnet with my brothers: https://github.com/otya128/winevdm
This is the proper Wine for Windows but just for DirectX->GL or DirectX-Vulkan.