I agree, that the amount of weight and G forces that the wing of a trainer can take is amazing! Trainers are very often set up with video systems, bomb drops, cameras, skis, floats, you name it, and wing reenforcement is usually not needed. These things can really take a beating! I have an LT-40 that weighs 10 lbs. with the floats installed and the wing hasn't failed me yet!

Trainers are awesome!