FYI an unexpected development this morning solved this issue.
I had intellectually surrendered and last night decided to just buy another video card & try some/anything different to just stab at any chance of having some/anything different.
Meanwhile, early this morning Windows 10 system software was remotely/automatically updated. When I woke the system up, whatever Microsoft had systemically addressed, brought the mouse's performance back from it's extended "vacation" vis-a-vis X-Plane & Microsoft's interconnectivity.
I functionally know little more than "diddle" about the "jigg-A-hertz" world you & your intellectual kin survive & thrive in, but intuitively thought the above awareness might possibly benefit your ongoing digital affairs.
Either way, the issue is solved and thank you graciously for your role played...mcf