4k resolution for Windows VM

I’m running 3840x2160 and have run

qvm-features dom0 gui-videoram-min $(xrandr --verbose | grep "Screen 0" | sed -e 's/.*current //' -e 's/\,.*//' | awk '{print $1*$3*4/1024}')

My Windows 2019 server vm was deployed with GitHub - elliotkillick/qvm-create-windows-qube: Spin up new Windows qubes quickly, effortlessly and securely on Qubes OS

Connecting to the GUI, windows gives me a max res of 2560x1600 (assume that’s a generic VGA driver and Qubes Windows Tools isn’t maintained).

I’m connecting via RDP to use the full resolution but wonder if there’s a performance penalty to doing that, or a better way? Thanks.

I have problems full screening VLC with a 3440x1440 ultra wide monitor. Goes black when i try fullscreen.
Just displaying a desktop shouldnt be that GPU intensive.

Is there any solution now?

Yes, I use xfreerdp to connect to the Windows VM via Remote Desktop (Windows Server 2019)

Can get full 4K resolution this way. You’ll need to follow the guide for inter-vm networking. (port 3389)

RDP to Windows(same machine) is very sluggish compared with using Windows directly, do you have this problem?

Yes, I also have this problem.
Rather than custom compiling Seabios, is there a workaround?