Finder won't "start"
(iMac Retina 4K 21.5 2017 - running Catalina 10.15.4)
Finder is not initializing properly - all I get is the spinning ball. I updated to 10.15.4 a few days ago and everything was fine until yesterday.
- I've completed PVRAM reset
 - Done recovery mode disk utility First Aid
 - Created new user account - Finder works normally on that account
 - With the assistance of phone support, gone in and deleted caches, pref lists, etc
 - Reinstalled the OS from recovery mode
 
I'm out of ideas. I am reluctant to restore from a recent back up until I have no other options.
iMac 21.5" 4K, macOS 10.15