Multiple PVE (Single-Node) Clusters with VMs and LXCs on Same Subnet: Alter NIC MAC Prefix Per Cluster?

(I'll preface this by saying I'm in a home server/homelab environment, so I realize this is probably not the correct enterprise production way to run things.) Anybody out there running multiple Proxmox clusters (single-node or otherwise) with VM and LXC containers whose vNICs share subnets? I'm trying to figure out if I need to give each cluster its own vNIC MAC prefix under Datacenter -> MAC…