I can confirm that this runs on proxmox. There is only one issue. With the cloudpath VM, it's easy to go to Linux and then install the qemu-guest-agent. How does one get to the CENTOS shell of VsZ?
I have been running vSZ on proxmox for a couple of years no with no problems. You do need to set the machine type as i440fx. Setting it as q35 causes the VM to reboot. At least that has been my experience. I have not looked into installing the qemu guest agent, however it would be nice to have.