I wish to include in my registration message to our server, a flag as to which APNS server is being used. sandbox or production. I wish to do this so that my code can simply look up the device token and notification server from the table of devices, so that continuing development can coexist with live devices.
The application does, in development, register properly, linking a customer ID in our system to the token string from the phone.
However, this does not allow me to determine programatically from our server which push notification server to use.
I’m not sure if I have your question right, but as per Apple’s doc Local and Push Notification Programming Guide: The Notification Payload
So all you need to do is craft your custom payload to indicate which server the notification was pushed from, and read it when it gets to the App.