Thank you for your always informative articles on so many topics.
The issue I have with this recent post (it claims to have been updated November 3, 2018) is that your GUI examples describe the use of a version of Disk Utility that has not existed in macOS (not macOS X any more, either) for many years. The current version of Disk Utility (v18.0) has none of the functionality you describe.
Personally, I manage my NFS mounts using the Finder’s Go/Connect to Server (⌘K).
In the entry box, type the destination: nfs:///,
This will mount /Volumes/Movies as a read-write network drive on my desktop.