WetGeek Not gonna focus on getting Manjaro installed on the Precision.
This episode prompted me to go back to the VMs and check to see whether I was remembering everything right. In fact, it turned out that the Plasma VM has the same problem as my experience with Plasma on the laptop. I had added the shares to /etc/fstab and installed nfs-utils, and everything worked great in the terminal.
I could cd to /mnt and list the mount points, and I could cd into them and list their contents. And I could use Dolphin -- via smb -- to connect to my NAS and navigate into the shares, opening them up to access their contents.
But although the mounted shares listed in Dolphin, trying to access their contents from there failed. Probably a permissions or ownership issue of some kind, but a reasonable amount of tinkering with it didn't bear fruit. And I wasn't sufficiently motivated to go beyond a reasonable amount of tinkering.
It was the Budgie VM that simply worked the way it was supposed to. 100%, without a hiccup. If I'd started out to make that laptop a Manjaro Budgie machine instead of a Manjaro Plasma machine, it'd be ready for prime time today.
I'm happy that it's now running on Solus Plasma, though. I happen to like eopkg, and don't care much at all for Pacman.