LibreELEC does not contain an NFS server, so creating an /etc/exports files has no use whatsoever. It does have Samba server built-in.
Is there no way to manually inject this?
I have the same concerns about SMB overheads, and would like to NFS share between multiple Kodi devices in my house.
My idea is to have a hdd plugged to separate Raspberry Pi's on my network - and then to share from 1 pi to another, without needing a 3rd device always powered up sharing over NFS - to me this sounds a lot more efficient than relying on SMB only