I am using
/mnt/raid *(rw,async,no_root_squash,fsid=0,crossmnt,no_subtree_check)
I did not investigate further, whether a (rw,async,root_squash,crossmnt,no_subtree_check) would be better.
As far as I understand, your NFS setup is done via a GUI without editing the /etc/exports file directly.
Maybe on your GUI you can select some of the options.