I set up to get just a tiny rise in RPM when I pinch. You have to make sure you do a quick pinch and release and don't pinch and hold waiting to hear a rise....because if you keep pinched it will riseor flameout sooner or later. When you fly a plane and make a hard turn you should hear a ever so slight raise in rpm when pulling a lot of "g"s. Or at least that's how I feel. The point as i see it is to have just enough richness to overcome a high-g caused lean condition. Otherwise if you tune to no increase at all on the pinch one has to assume it goes lean when pulling a lot of g~force?