Is there some documentation how to / best practice for ensuring that my Jenkins config is adequately backed up?
We periodically backup your JENKINS_HOME. You can read more information about it in the link below: DEV@cloud Backup Policies
However, we don’t provide these or allow you to manage these copies as they are only used by CloudBees for disaster recovery purposes.
We can install the standard Enterprise Backup plugin on DEV. This will allow you to backup so as long as you provide the storage (WebDAV or SFTP). Due to security reasons, we only allow backup for job configurations and build records. We don’t allow system configuration to be backed up. More information about how to use the Enterprise Backup plugin on DEV@cloud can be found on the KB article How to use the Enterprise Backup plugin on DEV@cloud
Notice, that we don’t allow customers to access to their instances to manage their JENKINS_HOME, and also there is not currently any feature in the GUI to let you upload a new configuration.