In Proxmox they have VirGL-GPU and Virtio-GPU. They allow VMs to pass work to the GPU without being dedicated to one VM. I don’t think gaming was the intended use case and don’t know what kind of performance you would get. My uninformed guess is that it would not be great.
Ceph. I have some Raspberry Pi’s that I’m going to set up a cluster with. Just haven’t gotten around to it yet. I half expect the performance to be relatively terrible, but maybe it won’t and I can try to build something on top of the cluster in a sort of hyper converged setup.
It’s completely overkill for a small home lab but that’s what makes it fun.