the question is not:"does it pump more?" The blue mylar, being less flexible will clearly pump less fuel if it is to pump against a zero pressure test vessel.
The question is: "does it pump enough?" As long as the available membrane surface/stroke can deliver all the gas an engine needs at the pressure that the regulator needs there will be no problem.
If I look at the amount of gas being pumped without the regulating needle installed, there is no doubt whatsoever in my mind that the blue membrane will do very well in engines of at least 150cc and probably even more. These engines most of the time have the larger carbs installed, which again have a larger membrane surface, so pumping quantity is never jeopardized.