All driven by table data in the ECM. If you look in HPT, they have uncovered this table... and RPM limit can be set for any gear, including Neutral. Good for limiting slip on hard 1st gear launches (and saving axles!), as well as if you turn them WAY down when the car goes into service where cars are often abused (I'm thinking of the myriad body shop stories where the emplyees are drag racing customer cars behind the building). Turning every gear down to 2500 RPM ensures they'll have a nice and piggy car to drive, that is still capable of actually getting on the highway if needed for legitimate reasons. Or, if you've discussed vehicle movement with the shop and they have ensured that it won't need to be moved more than from bay to bay, turning every gear down to 1500 RPM adds a little "trust but verify" factor.