Hopefully you will get good answer with this letter.
BTW regarding to this sentence:
The only way to use the launch control feature is to set the cars suspension, steering, and throttle response setting to “sport plus” and also to disengage the vehicles traction control. This is the only possible way to use the launch control, which the customer will know is functioning when the launch control indicator flag is visible on the vehicle dash board [Please see attachment #3.5].
For Launch Control you don't need to put suspension/steering in sport+; however I set them to sport+ for more fun
For LC all you need is S3 and DSC OFF