Not that hard to deal with honestly. Rebooting at night which I'm sleeping does not reduces any functionality, cuz I'm not using it. If someone needs to find me during the night he better call me cuz I won't wake up by notification which is also suppressed by DND. Yeah it is not design for security but a solution better than none.
Furthermore, rebooting the device periodically is good for security, especially for non-persistent fileless malware.
All I want to know is how safe it is, and how loud the sonic boom would be when flew over, not how expensive the ticket would be, nor "Will regular passengers be able to handle the physical effects of such high-speed travel."
I would just skip RAID, add all disk to a single BTRFS and use the built in profiles for (meta)data redundancy.
Cache I don't know much tho.
https://btrfs.readthedocs.io/en/latest/btrfs-device.html