Backup & restore w/external db and bookshelf

I’m building a OS Chef server in AWS, configuring RDS as the external PostgreSQL DB and S3 for Bookshelf. My goal is to ensure the data is safe and provide some degree of “auto-remediation” in case of an incident.
In this scenario, what data would still be stored in the Chef server itself ? Can i take a snapshot of the server just after the initial installation and use that to build a new instance if needed or would i lose any data ?
I was thinking on creating the Chef server instance with an autoscale group with minimum and maximum 1 node, using an image taken just after installation, to have it launch a new instance if the one running dies.
The Chef documentation says that you should use “knife ec backup” if you are using an external database but is that the only option ? That project seems a little offline atm…