How can I use POSIX ACLs on an NFSv4 mount in Linux?
There are patches for libacl to do some kind of mapping between nfs4 and Posix ACLs. They seem to be unmaintained. I've never tried it.
http://www.citi.umich.edu/projects/nfsv4/linux/acl-patches/
http://www.citi.umich.edu/projects/nfsv4/linux/using-acls.html
https://datatracker.ietf.org/doc/html/draft-ietf-nfsv4-acl-mapping-05