I don't like your backup strategy, but I do like your method of limiting yourself from accessing certain distractions! Here's a tip for both:
BACKUPS
Use an app like S3Drive to automatically perform client-side encrypted backups to a host of your choosing (rclone compatible).
RANDOM PASSWORD
Use a USB device that can act as a keyboard and program it to output a long random string you won't remember. Combine this with a PIN or password you do memorize. Now to access the owner account, you input the part you memorized and insert the USB device to add the part you won't ever memorize (store that part in a password manager too so you won't be locked out by hardware failure).
One such device is a YubiKey 5, which is the size of a very small/flat USB stick.
Remember to allow USB devices when your phone is locked before setting this up, or you'll be going through the excruciating excercise of typing your long random password manually 😅
Come to think of it, this is also a great way to travel with your phone on a restricted profile while being unable to give anyone (e.g. law enforcement, [other] criminals) access to your owner profile. You just leave the USB key at home!