If anyone on Windows would like to see what performance is like, I updated my WSL installer scripts to use this version of XRDP.

Ubuntu XFCE: https://github.com/DesktopECHO/xWSL

KDE Neon: https://github.com/DesktopECHO/kWSL

Kali: https://github.com/DesktopECHO/Kali-xRDP

These scripts will build a complete RDP-accessible Linux desktop environment in WSL. A GPU isn't needed to see a significant performance gain over 'stock' XRDP.