I'm not saying you recommended it, but since you mentioned it in passing, I'd like to ask us all not to book a bogus extra leg (one you don't actually plan to use) to South America to save 2500 miles. That's the kind of abuse that will lead American to kill for everyone this nice feature in their award program. First, from their point of view, it takes a seat out of inventory that could have been used to satisfy another customer with reward or paid travel. Second, from the point of view of that other passenger (which could be me, or could be you yourself next time), it will deprive him or her of the opportunity to get the seat. Third, this does amount to a change in destination if you don't fly that leg, and AA would have every right to come after you for an itinerary change fee plus those miles you thought you saved.

I understand we all work the system, but I think when the benefits are quite minor and the potential harms to both yourself and others are significant, it's best not to always try to get the last drop of blood out of an opportunity.