Good on US-AA for cleaning up the boarding process. And good on FAA for stepping up its enforcement against air carriers, which is leading to the enforcement of pretty simple rules.
Rather than delaying the boarding process for those who don't know how to use a tape measure, pull them out of the boarding queue and let them wait until others have boarded. At that point, tag the bags to the baggage office of the final destination where they can be picked up after paying the baggage fees and a processing penalty.
The violators here tend not to be little old ladies who never fly. It is frequent flyers who know the rules, flaunt them and can be -- just like Pavlov's dog -- trained.