There are reports of a few games running better under Linux with Wine than natively on Windows... I wonder if when MS's DX12 translation is finished that performance increase will carry over.

Actually, there are games that run better with Wine under Windows than native... I mean, there are some games that work better when you use the OpenGL based DirectX implementation of Wine than the native Windows version, notably Dracula 3 on Windows 10 requires the "Wine D3D For Windows" project.

At one point I tried running Wine in WSL, hooked up to VcXsrv for GUI, using Qemu because WSL1 didn't support 32-bit apps. It almost worked, but audio wouldn't play, and the desktop size was wrong and parts of apps wouldn't redraw.

Can confirm: it still does.