My eventual hope for GUI-VM support would be something what exists with Chrome OS / Crostini, which runs Linux containers managed by LXD within their own VM. The solution includes virtual GPU support, passing sound out of the container, solution for mounting files and external drivers. Also, GUI apps with “.desktop” files get surfaced in the host’s launcher and will launch the VM to run the app if needed.
They narrowed their scope of integration work by focusing primarily on one VM running one container with GUI integration.