Thanks for your reply, ghr165, and I apologize for my late response.
To clarify, I'm not concerned about an accidental reinstall. I'm concerned about a MANDATORY reinstall. If the Safe Mode boot process triggers a reinstall based on what is encountered during the Safe Mode boot process, I may not be able to back out of it without reinstalling macOS.
Before I try Safe Mode I would like to perform any available Contacts repair or maintenance procedures OTHER THAN Safe Mode restart. If deleting Contacts, reducing Contact note field content (some of mine are large), or deleting Contacts Groups I would like to do that first before attempting a Safe Mode restart.
I only recently learned that apparently there are Card count and size limits. I have been using many of the same Contacts for many years. Are procedures or reports available to determine how close I am to these limits on my MacBook Pro M1?
All suggestions welcomed.