well...renault certainly does know abit more than the rest about getting away from the line.And as they where the class of the field with launch control and assuming they don´t cheat ,their starts where lightning because of better clutch /engine control strategy but not the automated launch sequence.
Obviously everybody else were sleeping and thought
f course ...they have a lower CG height ,due to the low engine ...and they might have a better torque spread and sacrify topendhorsepower...
But now everybody is awake:It has to be the clutch or the strategy how you feed the revs and power.My bet is :clutch .