There is no harm as long as you know how to drive uphill and especially downhill on auto transmission vehicle. I have gone there recently on a 2400cc auto, no problem at all.
While descending, never ever use "D". Always use "L" or "B" on some cars like Vitz. Apply brakes as little as possible and when you have to apply, use hard braking to slow down the vehicle in a minimum possible time and release the brakes.
If you use continuous braking, the brakes will fail soon.
