Pretty sure they're not intended to actually launch. I'd bet that doing it over and over is just going to destroy your transmission. If it was intended to be launched, they would have added a Launch Control mode like the GT-Rs have.
If I'm remembering correctly, the old GT-Rs had transmission failures because of the stress that launching (foot on brake and gas at same time) places on the transmission.
Ultimately your call if you want to lunch your transmission, but just something to keep in mind
