For the S10, the aftermarket QS, it is only Up (cutting injection or ignition)….for a down QS, you need to “accelerate” the engine to match speed with wheel rotation…that is done only with ecu software (which does not exist on the market)…”but” in down, you lose the engine brake…..The one I have is only sold in my country (because it is manufactured here)….it has multiple actuator sensitivity adjustments…and multiple time adjustments (in milliseconds), injection/ignition cutoff…..”for me”, it is another motorcycle…much more agile for overtaking and on mountain roads….it is more fun….”but”, it is essential that the QS has multiple regulations, otherwise, you will not find the exact point so that the gear shift, is smooth….