AFAIK: The way DX9 works for Windows software running under Wine, is that wine has a layer that intercepts all DX9 calls and retranslates them into OpenGL. There is no equivalent for DX11.
No clue. I was making an educated guess. I was stuck with DX9 for a while because I wanted some stuff to run under wine. I switched to opengl nearly... 6 years ago now? Didn't realize it had been that long.
[1] https://www.omgubuntu.co.uk/2018/01/wine-3-0-released-direct...