Actually on a tandem axle trailer, just moving height of the rearmost axle would suffice I suspect for ease of loading a car. The torsion axles are fairly low to begin with. That ought to be doable for a DIY'r, and does sound like a nice feature. OEM, is likely big bucks, and I understand much harder to justify.

Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.