Originally Posted by JS
Something else to consider is what happens if AA detects the duplicate reservations? (e.g., if your departure dates are the same) They will not be happy about that, and they do have programs in place that search for duplicate reservations (e.g., people who book two refundable tickets because they're not sure which one they really want). Airlines, as well as your fellow potential passengers, don't like it when people soak up inventory unnecessarily.
Funny you should mention that, JS. That is what got the whole discussion rolling on the AA forum. I initially set-up the awards over the same period (no overlapping flights), and was scheudle to fly from the N. America to LHR on two different flights (and carriers) on the same day. I was told by AA that that wouldn't work and one would be canceled. As such, I moved up one of the trips to avoid having them overlap.