Hello @bomdomqw1 , i had read that there is a backup tool for the settings, and with the initializing (screen procedure) of a newly installed/flashed OS there is the question similar to “would you be loading a setting backup file?” I did not make a backup, unfortunatelly.
Backup Apps are a security risk: How backup with iodéOS recovery - #12 by shumafuk
You find the serial number inside the phone under the battery, also after remove the battery.
Let use wait for the next update (2.21).