When new computer programs adjust the gears torque-wise, they lack intelligence to plan for engine cooling on long grades.
It was common on older heavy sets that well pulling engine will overheat 1/2 the way up the mountain and easy prevention was force it to drop couple of gears when starting and not going faster than 1/2 throttle.
This way higher rpm with less load provide for better engine cooling.
Same going downhill, when even with engine brake and speed controlling program, you might face situation that will call for more downshifting.