RV circuit boards could be designed for a greater AC voltage tolerance. Ditto For DC circuit boards. Ditto for AC and DC motors.
And what about home appliances some of which need DC or a battery for clocks in a RV?
I doubt that US/Canadian owners want to spend the extra dollars that would be involved. Those going to Mexico might be willing to spend extra from the factory but I suspect they represent a small portion of the RV market.
I added a power protector that guards against low/high voltage. I could add a autoformer for low voltage boost. If I was going to spend time in Mexico I would definitely be in the market for the devices being discussed on this thread. Thanks for the information.