I appreciate the simplicity, but giving such broad permissions makes me unease and the main reason why I'm putting off moving to Nextcloud AIO. Am I the only one who thinks like this?

Thank you for this. I really dislike MySQL/MariaDB and favor SQLite whenever possible, or PostgreSQL otherwise. The DB migration of my Nextcloud instance was high in my to-do list, and your instructions saved me research time.

Thank you for the link and the Redis pointers. I should double check that my Nextcloud setup is using Redis, it might well be misconfigured.