SA Mode on:

If worried your bag will not get proper attention find the loudest wind-up alarm clock and set it for 30 mintues prior to take off. You might be released before your return flight.

SA Mode off:

If it is a soft-sided bag, then do find something to "prop" it up that doesn't need to make the turn trip. A good option would be beach balls or other inflatable (resisting SA Mode again), that can be deflated once the bag is filled.

Another option would be to pickup a cheap bag at your destination and use it for the return.

Enjoy your trip.