I hadn’t had any of the reported issues…
Then Win 10 updated itself and I got stuttering cursor, random jumping away from where I picked etc - in SketchUp, but also in web-browsers etc.
I updated my Nvidia GC drivers, things eased, BUT not completely.
I then did some digging…
I had an unused driver installed - ‘Realtek Audio’ [a legit app] - I uninstalled it, and after a restart things were fixed.
Seems that even when it’s not active it can get something called FMAPP.exe running in the background.
This captures mouse-moves and keystrokes [which sounds like a key-logger Trojan to me !], and in turn that messes with all manner of things…
Anyway so far so good, mouse back to normal…
Note:
Most of the Realtek driver subfolder’s files was emptied by the uninstall.
But then I had to delete its DriverStore subfolder, which contained two left over FMAPP.exe and dll files - after some convoluted permission/ownership tweaks - otherwise they are owned by ‘System’…