How to set up a shared NFS directory for Raspberry pi pxe clients?

Question

PXE

Configured the Rasbery pi to boot over the network (used as an RDP thin client). NFS gives away the root of the file system.

/etc/exports:

/nfs/user1 *(rw,sync,no_subtree_check,no_root_squash)

cmdline.txt:

console=serial0,115200 console=tty root=/dev/nfs nfsroot=10.10.10.40:/nfs/user1,vers=3 rw ip=dhcp rootwait elevator=deadline

In the case of one client, everything loads and works.
If new clients will boot from the same nfs root:
/nfs/user1 - there will definitely be problems when these pxe clients work. The output will be to allocate for each new user a new directory on the NFS server with a copy of the file system (~ 1.5 GB) and everything will be ok.

But suddenly someone figured out how to distribute one common root of the file system via nfs for several users. It would be cool if in cmdline.txt you could pull a script (before mounting nfsroot) that would start a docker container with an nfs server and another tcp port.

I would be grateful for any advice/thought