Gas and oxygen pressures are easy to control by following the manufacturer's recommended pressures for the size tip and metal thickness. The cutting speed and vertical or horizontal movement , however, are much harder to control. The Steady Guide controls the vertical and horizontal variables, so all the user has to control is cutting speed. Cutting speed controls preheat. So if your speed is right, the preheat is too.
Irregular surfaces are no problem because the torch tip is constant at any angle to the workpiece.