not much harm cuz when you stomp on it in d4, it shifts right at redline or a little before it anyways. if you want a better launch in an auto just brake torque to about 2k rpm in d3 and mash the gas and and shift it at redline. that how i launch when im on the bottle . tire spin is still pretty bad even tho im rolling already but its not as bad as if i just stomp and spray.