rather deeper rabbit hole than installing 3 x proxmox, i think..but it exists...https://warewulf.org/ https://warewulf.org/ lots of other stuff will do the "bo

rather deeper rabbit hole than installing 3 x proxmox, i think..but it exists...https://warewulf.org/ https://warewulf.org/ lots of other stuff will do the "boot from single image" part...say...https://fogproject.org/ https://fogproject.org/