Nebula rollback options in case of malicious admin action

Hello,

We manage a Nebula deployment with 200+ sites and expect to add 600+ more. We’d like to understand what recovery options exist if an administrator with malicious intent deletes all sites and backups.

Specifically:

• Is there a rollback or restore mechanism for Nebula itself?
• If needed, can Zyxel support assist with a rollback?