Further troubleshooting with positive result at end:
-found and purged 760mb of images/files directly from the creative cloud app (never directy uploaded to this before)
-logged out of lightroom classic, logged out of lightroom cc on all devices, logged out of creative cloud
-shut down computer, NVRAM/PRAM/SMC reset, -logged back into apps, LR-classic still crashes every 10 seconds, and it's been over 1 hour since purging all of the data from the LR-sync via the lightroom.adobe.com interface.
-Rolled back from latest version to previous (13.0), still crashes every 10 seconds.
-Upgraded to latest version, still crashes.
-Backed up catalogs and uninstalled LR-classic, rebooted, reinstalled 13.0, still crashes
-Removed catalog file “LR5catalog-v13 Sync.lrdata”, still crashes
-REmoved all catalog files from the LR-classic working directory, started Lightroom, started a new catalog, it remains stable. Switching back to the previous catalog still results in instant crashing, so the problem catalog level or a corrupt image
-LR stable with new catalog, imported everything from previous catalog into new catalog, stable, re-adjusted general settings, found missing folders, LR was running background processes to update the catalog hierarchy… and then it crashed. Attempted to restart LR-classic after crash and it just hung on the splash screen, spinning pinwheel, force quit, and restarted. I was finally able to trace down the crashing to the last image I was editing when the original crash occurred; ultimately deleting this image from the disk and catalog has resolved the crashing as far as I can tell. The last edit contained a few basic adjustments, a radial gradient for exposure, and another radial gradient with the new point-color feature in use. Maybe something to do with the point-color tool?