atleast part of that statement is true. but, its has nothing to do with the valve.the jumper mod is for the exhaust valve, which the 04 and earlier zx6r's don't have....so no.
the valve is uneffected by the jumper mod. since the jumper mod still shows an increase even with an aftermarket pipe. in which case, the valve is eliminated.The jumper mod I am aware of refers to the valve in the muffler of the 05+ 636 that closes at 13K rpm. Installing the jumper tells the ecu that it is a UK bike and leaves the valve open all the way to redline.
Is there something I'm missing?
well, the theory of low end is no longer a theory. it(valve) does NOT help, in fact it hurts it.it does every thing u said and the valve u dont notice it on a aftermarket exhaust cause if already flows better.
the valve in theory helps with lowend and emmison.