It's been three months since my initial post above. None of the listed tips worked.
What has worked is covering the track pad with enough layers of plastic to desensitize the surface, but not so much that the track pad doesn't work.
I used lamination sheets one sheet tucked inside another (so 4 layers) then run through the laminator. Only problem was the surface has too much friction.
At the moment I have a trackpad 'skin' (total waste of money) and a white plastic (pvc?) new car dealer license plate insert. This has a nice slide, but I do get an occasional random cursor jump. The track pad still works fine. Any other 'solution' than covering the track pad did not work, though it might seem so but not for long.
Doing nothing or using one of these other methods: I got a random cursor jump every minute or two. (Apple also replaced the entire machine, though no hardware problems showed up in the tests. Both machines acted exactly the same.)
It made writing nearly impossible. I can take these plastic coverings on and off and duplicate the error or eliminate it.
With the double-laminates the problem was completely eliminated-but the surface was sticky. I've also stacked 4-6 pieces of laserjet paper and even used a Tyvek post office envelop (doubled)
With my current solution, that still occasionally jumps, I could slip a single melted laminate sheet underneath the white pcv and I think it would completely solve the problem. The pvc and the laminate (when I tried that) are held in place with Scotch tape. I made it oversize which also makes the trackpad waterproof. I think it's pretty lame that Apple had no solution or even awareness of this problem. On MacRumors someone suggested keeping an old MacBook Pro that still works. Also the TouchBar is too sensitive, but not random. I've eliminated almost all the buttons and turned of configuration changes with App changes. It may be useful with some specific apps; in general it's a piece of hardware with no killer app. I do like the fingerprint password function. Hope this helps.