Thanks everyone. So the answer to my question in this thread is definitively NO because Moodle needs SHARED caches for MOST of the application cache mappings.
"Unpredictable results" is a bad thing.
I did find there are some mapping in the application cache that CAN be mapped to local storage. A bit hard to find in the admin>plugins>configuration>known cache definitions. If you edit the coursemodinfo application cache mapping it says:
This cache can be safely mapped to a store that is local to each webserver
And there are some more that can be mapped to a local RAMDISK without problems. With slow NFS it is still faster that a (remote) redis cache.