Based on some of your work (thanks) I've got 4xPi4-4gb booting from a fifth Pi4-2gb that is running dnsmasq (PXE only) and NFS for / and /boot. Boot order is 0

Based on some of your work (thanks) I've got 4xPi4-4gb booting from a fifth Pi4-2gb that is running dnsmasq (PXE only) and NFS for / and /boot. Boot order is 0xf412 - network, SD, Usb, repeat. The /nfs/tftpboot/<host_serial> is a soft link to the boot directory inside /nfs/<imagename>-<hostname> Each host gets its own directory - haven't looked into a CoW filesystem yet. I've got a hacky Ansible script that will reboot a specific host from network, dd a fresh Raspios image onto the sd card, mount the root filesystem, copy over the ssh keys, reboot the pi, do the usual apt update/upgrade and a couple other tweaks, reboot from the network, dd the sd card back to an image and finally run Pishrink.sh on it. It's fascinating to watch in a Rube Goldberg kinda way. I would add that net bandwidth seems quite respectable though not USB3 speeds. One issue i've run into is that K3S does not start - mostly likely due latencies with networked disks