I have just done some date/time changes to flights on a Cairo originating ATW ticket which was issued by Qantas and travel not yet commenced. Took about 5 minutes on the phone to get the flights booked and tickets issued within a few minutes

Would recommned Qantas over AA for ATW tickets in general - can phone up , make booking, get tickets priced and payment taken all in one phone call , with the tickets then arriving within a few minutes