I want to build a whole new server, starting with a wooden case that makes it perfectly silent (but allows for good air flow).

Btw: does anybody know what bad things actually happen if there is no metal cage that blocks all the radio?

ip 10.0.0.1.1/8

This one was created by AI, right? 😉

I can not get my host node (the one that is 10.0.0.1/8 in vmbr1) to communicate with that NFS share.

Go through the usual debugging steps like:

Can they ping each other? Is the NFS access restricted to certain hosts? Is your NFS mount command correct? Is the service really running when you try the mount?