I've never actually had to utilize a SDC, but have cancelled and rescheduled a flight. For me, I just cancelled it via my AS app, then called a few days later to request the flight credit back. Then, just booked another Vegas trip with the 14-day limitation. Again, for me, I go so often that the 14-day restriction has never posed an issue; so, clearly for me, it's one of those things where something that's important & valuable to them isn't to me, and easy to use as a bargaining chip.