To answer my own questions:
The nfsPVC section in the datahub setup is specific to the datahub setup, and abstracts out creation of NFS PersistentVolume and PersistentVolumeClaim parameters.
Adding NFS proved relatively straightfoward. Our config is here:
with some notes on getting storage working in storage.md. The actual NFS setup is in init_nfs.sh and used in the config.yaml.