I got NFS to work correctly so I could consistently CLI mount the SD Card I shared out. I even verified by using the following bash command at each leaf:

echo $HOSTNAME > /mnt/nfs/$HOSTNAME

Then I screwed one up by troubleshooting the inability to automount the NFS share at bootup. Meh. At this point, I think maybe I'll just image the still working leaf and write it to the non-working one, then go thru raspi-config and rename the host back. I don't feel like dealing with cables.

I forgot to mention that I'm currently using wifi, and that may be the problem with automounting.

Yeah, I think I'll do that, then make sure I can run MPI tests, THEN try and figure out the problem with the RJ45 dongles.