Even aviation has how to change the what a flying object can or can not do.
Like the Chinnok copter operator that needed to get to 20k feet on McKinley to rescue someone. They had a 15k spec. Manufacture sent them a 20k spec. Ie lower weight, lower hrs inspections. So away.They went.
Weight.laws in the US any how, DO NOT enforce manufactures ratings. Only road bed max ratings. BenK designing a truck, and spec, is not what is enforced. It is BenK's road bed engineered ability to carry the load that is enforced. Until one wraps their head around this, you will not understand the reason behind enforced ratings.
Marty