Thank you for the followup. It's frankly amazing how so many knowledgeable people like you have stepped up to help everyone. I'm appalled at how long it's taken me to notice your kind reply and send this response. Also at how far over my head your suggestion has flown, despite reading it several times. By way of explaining my delay, the Costco Dell is going back (several deal breaker physical design issues). So now I'm trying to get Ubuntu MATE 20.10 working on the 2010 MacBook (just posted a pathetic cry for help on that).
So long story slightly shorter:
- My limited brain power is now directed to getting MacBook onto MATE 20.10 today.
- The 1TB SATA SSD was working just fine and MATE was running like a gazelle, so I'd have been reluctant to tempt fate by messing with fstab.