You can use the iGPUs resources for VMs while unraid is also still able to use them, yes.
Just connect via a service like sunshine/moonlight, parsec, rdp or vnc. If you need a physical monitor use an usb to hdmi dongle.
But keep in mind, this plugin relies on a repo which seems to be no longer maintained.
So don't just sell your gpu atm ๐
Once there is more information about the future of this plugin, it will be posted here.