Yes! Thanks Deano and Sauerland!
Leap 16 share works with vers=3. Tested on fstab:
192.168.0.3:/home/bruno/share /home/bruno/share nfs vers=XXX,soft,noauto,rw,users,timeo=100,retrans=200 0 0
where, on LEAP 16:
XXX=4.2 → readonly (Dolphin properties panel: filesystem nfs4)
XXX=4 → readonly (Dolphin properties panel: filesystem nfs4)
XXX=3 → writable! (Dolphin properties panel: filesystem nfs)
On LEAP 15.6 all three version options are writable.