One of the features I would like to see in a FortiGate is the ability to automatically create backups and copy them to offline storage. Of course, this can be accomplished by adding FortiManager to the solution, but why would I need FortiManager if I only have one FortiGate (cluster). Another option would be using scripts, like Python or PowerShell, with scheduled tasks on servers to pull a backup from the FortiGate firewalls.
A very basic option would be the usage of system auto-script in FortiOS 5.4 and higher. Use this command to create CLI command scripts that can be saved and run. This gives you the possibility to auto-script the execute backup full-config commando. A disadvantage of this command is that you only have the option to use (T)FTP. There is no option to use a secure protocol like SFTP.
An example of an auto-script:
The script can also be configured via the GUI (Global >> System >> Advanced >> Configuration Scripts). More information about the feature can be found here.