NixOS has a related problem in that you can't set the machine's MAC address without a hack:

      # Hack: Change the default MAC address after network but before dhcpcd runs
      systemd.services.setmacaddr = {
        script = ''
          /run/current-system/sw/bin/ip link set dev eth0 address ${macaddr}
          /run/current-system/sw/bin/systemctl stop dhcpcd.service
          /run/current-system/sw/bin/ip addr flush eth0
          /run/current-system/sw/bin/systemctl start dhcpcd.service
        '';
        wantedBy = [ "basic.target" ];
        after = [ "dhcpcd.service" ];
      };

If you don't do this, it uses some black magic to decide the MAC address based on various hardware, making system migration and maintenance a nightmare.