Essentially this is for having different values based on run mode configurations. Not for production environment.
For example, I am taking the a sample implementation created by Jörg here. If I want to overwrite the value of the property 'approverGroup' in caconfig filefollowing the above doc by providing a run mode config for the factory for e.g org.apache.sling.caconfig.impl.override.OsgiConfigurationOverrideProvider-test1. Is the value for 'overrides' property something like this to do the job. I tried below and it doesn't seem to work. Or am I missing something else?