After spending a lot of time, without any success, trying to make the code suggested to have Gramps actually install the necessary packages for my displayMetadata & pyExiftool requisites, I have given up.
This was prompted in large part after coming across the comments in Where is the Gramps distribution of Python on Windows? - #5 by PLegoux and more specifically by the comments in
0010913: Face detection in Photo Tagging Gramplet (Does NOT work in the[Microsoft Windows] AIO bundle(s)) - Gramps - Bugtracker – Free Genealogy Software
As it turned out, I realized that displayMetadata does in fact also need numpy.
There is just no way I can take on the effort to even build Gramps from the ground up as suggested in the first link
https://www.gramps-project.org/wiki/index.php/Gramps_for_Windows_with_MSYS2
As well, at this time I don’t see that approach being workable for me, if only because, if I want to the plugin to be usable by others, they also would have to go the same direction. Of course, the Photo Tagging gramplet also looks attractive - more work.
While I am still weighing my options, going forward with a Linux only solution looks simpler than trying to keep ‘working around’ the Win/Lin differences.