Greetings! @attila
Well my apologies for the time delay of my response.
So the story so far, the steps from my initial post brought no joy.
However, a glimmer of hope appeared; having Windows10 in a VM, I installed Waveforms. Well whadya' know everything worked as advertised right outta' the box, huzzah! Hmmmm. . .,that was also a bit odd I thought.
Further investigation yesterday yielded the MacOS result while using a laptop running Big Sur 1164. At this point I knew the Digital Discovery device was functional as the Win10-VM sanity check indicated.
Looking further in WF app / Help / Digital Discovery / Troubleshooting, I came across a little tidbit that has resolved all the issues with MacOS/WaveForms interfacing. Specifically attach the DD to an available USB port but, ABSOLUTELY NO leads attached to the device. Then 'fire-up' the WF app, well looky there, WF now recognizes the DD, much joy!
As some further sanity checks, this repeated two more times on alternate USB with the same results. Then tried the laptop: A.O.K.
As of yesterday afternoon, I would say we're golden here.
Will this repeat itself another day/different phase of the moon? "I certainly hope so Ollie!" {Laurel&Hardy reference for you younger players at home.}
Thank you for the timely response attila, I appreciate that muchly.