Excellent post ivoR. !
I have a similar setup, but ran into firewall issues on my NFS server. LE would try to mount my NFS shares on random port numbers, which were of course blocked by the firewall. Everything works once I disable the firewall.
Is your NFS server firewalled? If so, how did you make it work?
I've not yet found any way to control the expected NFS port from within LE.