I wonder if the ‘At storage attach’ event will work for this case in GA.
Probably not in this case? The 'at storage attach' would fire when it sees a connection to the path is established correct? Unless it has a "floor" for connection speed, then it will connect regardless if the connection is a 10GB or 128KB per sec.
Question at hand is making sure their is a 'min speed' requirement so the backup doesn't take eons...theoretically. (However as long as a full backup is not performed, the backup should not take that long unless they are running it on dial-up!)