Macos KVM - in a window or GPU -> monitor only?

Im looking at maybe setting up a macos KVM vm but I’m wondering if I need a second monitor, or could I “view” the macos KVM same as a linux vm?

No, you can just VNC into it like you would on a regular VM. Performance is very bad though. I suppose good enough to run XCode builds, but not much more than that.
What’s the use case for the VM?