Thanks for following this!
I am going to wipe my disk and reinstall catalina.
I installed the latest catalina, 10.15.5 and things appear "more stable". I got a crash in Melda but not in Modo, mind you, I kept away from it mostly
.
The latest catalina now has a looping "killall" mds process that I could figure out, but would rather wipe and restart. I'm going to be careful to keep minimum installations on it. It's so easy to go over board and when you have problems it's very hard to unwind what you did.
Getting sick of Mac and Tower is ridiculous, am researching PC build with Ryzen. That's the subject for another thread.