Winapps do not make passthrough of GPU or there is no hardware acceleration it rendering in software way only basically if u are using even podman or docker or libvirtd in the end it qemu with windows in which u connect by rdp.
About rdp ,
- make sure that OEM scripts was successful executed in windows ,they should appear at C:\oem
- Do not forget to clean certificate of freerdp on host system there mention about it on github wiki of winapps
- Preferable use something like tiny11.iso