In the USA on the E46 there is no limit on the number of launches you can do and it does not void the warranty but the launch RPM is lowered to reduce the wear and tear. I was told the computer actually performs a many engage-disengage sequences that increases wear but i could never tell. I have done this many times and at one point had the clutch replaced (for unrelated reasons) and the clutch did not show any wear after all the abuse. Maybe the gearbox is another story
Outside the USA the launch RPM is higher but once you have used launch mode three dozen times orso, it will not work anymore until the dealer clears the s/w latch which will void the warranty.
I am very curious to hear how the E9x differs in this regard.
Also, on the E46 you can control whether to launch with maximum traction or maximum torque. The latter will draw nice black lines on the tarmac but you will go nowhere fast
. Is such control available on the E9x?