Editing extended property settings

We had talked a while ago about using the server.cnf as a means of storing environment-specific settings (eg. ftpServerHost, environment (dev/prod, etc)) to avoid hardcoding values in the flow services.

I’ve been able add my own properties to this file using the Administrator by prefixing my keys with ‘watt’ such as watt.ftpHost=someHost. However when I add a key such as myFtpHost=someHost I don’t see the property anywhere - it’s gone after I save the changes. Does anyone know how this extended settings section works?