I recently bought a 4 place jet ski trailer. It is low to the ground, has Torsion suspension with dual axels with 12 inch wheels and it's all aluminum. Very light and low to the ground. Drawbacks? a bit expensive and not readily available. -Tom, South Jersey. ( How are you Nick W. ?)
Mine was rated for a 16ft boat. I replaced the leaf springs with 1000lb springs from TractorSupply and moved them as far back as I could to get the proper tongue weight.
Yes. The stock springs are rated for carrying a 16 ft power boat which is much heavier than Kitfox. The stiffer the springs, the more jarring the ride is going to be for the airplane. Also, because I'm towing with the airplane backwards. the center of mass of the airplane would have been behind the axles with the stock position. I was going for a tongue weight around 10% of the total weight.