Ya! You can use VMs that use X11 in the guest without issue. X11 also works on the host. Wayland is also working on the host - I haven't tested yet with Wayland

Ya! You can use VMs that use X11 in the guest without issue. X11 also works on the host. Wayland is also working on the host - I haven't tested yet with Wayland guests yet so that's something to try.