While your calibration profiles for headphones are a good average for individual forms ouf human ears, allowing some adjustments would further impoove the experience.
It would be helpful to have a adjustment for the critical level at 3Khz in the range of a few db.
Whenever the sound color of my calibrated headphone didnt match that of my calibrated monitors, i could addjust by chamging response at the ear channel resonance within less than +- 2dB.
Because on differnt sizes of your ars the coupling of the transducer to the ear channel resonance varies specially with small transducer in headphones.
In addition the frequ. of the ear channel resonace varies from people to people.