Yes, I agree with you totally, Jicehem. I would (though I am not an aerodynamic engineer) have done just that, added camber on the left wing rather than more span. Of course, with added area over the right wing the longer wing would have more lift, but also more drag. I'm not sure why the designers went this route, but it is an interesting bit of information!
In fact, I have "real world" experience with changes in wingtip camber as a I once inspected an older Mooney that had a repair to the left wing near the tip that increased lift. The repairman then adjusted the right flap to overcome the extra lift on the left wing and the airplane flew crooked for years. The new owner (who I had done the pre-purchase inspection for) re-repaired the wingtip and rigging then went back to completely normal.
