Always remember: RAID is not a backup.
Having only one backup and the server dying means you now have no backup, therefore the 3-2-1 scheme for backups is worth looking into.
That depends a lot on what you're hosting resp. if the mobile apps are using Google's/Apple's messaging/notification services.
Not sure if it makes things easier than your current setup, but take a look at Mediathekwebview.de
The official NC docker container uses the "www-data" internally to run the services. This will get important if you ever want to run tasks via "docker compose exec".
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