Tablo really needs to come up with a way to perform a periodic backup of whatever system files are needed to recover an external drives content back to a Tablo device. Obviously an external drive would be a requirement and only the content that exists on the external drive would be recoverable, especially for those situations where the Tablo device has a malfunction and the only recovery possible is a factory reset or a device replacement.
Even if Tablo stored an encrypted set of system files that only they can decrypt and use in recovery/rebuild of what is necessary to recover the content stored on the external drive back to being accessible once the Tablo device is back up and running again.