LibreELEC and NFS

Hi

I’m testing LibreELEC (Krypton) v7.90.010 ALPHA and I’m having problem configuring LibreELEC to mount a NFS share. On another Kodi/Jarvis instance I configured the NFS share directly in /etc/fstab but in LibreELEC that doesn’t seems to be possible as /etc is read-only. And I couldn’t get NFS through the GUI configuration to work until I tested with turning the firewall completely off on the NFS server.

This leaves me with three questions
– It’s not possible to use /etc/fstab to mount a NFS share?
– What NFS client version does LibreELEC come with?
– What ports does it rely on?