Thanks for the write up. I'll follow those steps over time.
I did reinstall catalina from recovery, and lots of other maintenance. The problem persists (and lots of others, but things seem a little better overall).
Regarding the window resizing, I've been documenting more and more quick fixes, hoping they might give some clues.
- restarting KM engine
- restarting whatever app has the problem
- switching clamshell mode. for example if the laptop is open (mirrored to external) and i close it, the problem temporarily goes away.