These headphones have a DSP that continually reconfigures the response, I'm not sure that any synthetically generated frequency response curve would actually mean anything.
Not criticizing, just stating OPs argument.
... and you cant measure it is at the heart of all audiophoolery. Either it reproduces source material as close to 1:1, or it distorts it tricking your psychoacoustic system to perceive a positive difference, for example by making the sound louder (wins every single blind test).