I understand. I wasn't thinking you was referring to an automatic transmission. Want to hear something funny. My Mom and Dad use to call this shifting of the transmission, "Passing gear". Yep, I was just a kid and knew nothing about this and well, made sense. Yep, passing gear.An automatic transmission will kick down to a lower gear when conditions are right and you step on the gas. This gives you more torque and thus more acceleration (at the expense of higher RPM). S3XY Buttons copied this idea. If this feature is enabled and you are in Chill mode then when you step on the accelerator it switches to Standard or Sport, giving you more acceleration. So yes, it is like a sudden nitrous oxide boost.
TIP: I have to set to kick in when the pedal is depressed 90%. I original had it set to only kick in at 100% but that gave an emulation of turbo lag.