Correct, the height adjust simply sets where the wheel makes contact with the toe/heel. There is no change in the pressure applied to the blade during sharpening.
As it's been explained to me. Due to the natural shape of the blade, sharpening with the toe to the right allows you to set the height higher and sharpen further up the toe.
If you're curious, manually move the wheel to just before it would make contact with the steel in both directions. Either way, it does not affect the actual sharpening. You're still getting two passes per cycle.