Implementing headphone transfer function (HPTF)
Properly equalization improves the spectral accuracy of a binaural playback. It does not improve the spatial properties of the HRTFs other than that vertical localization is heavily dependent on proper spectral playback.

The best headphones for binaural playback tend to be diffuse field equalized and "acoustically open". This means that the headphone itself doesn't change the acoustic radiation impedance as seen from the ear canal into the outside world. It can actually be shown that headsets that are "acoustically open" do not require specific headphone equalization.

I'm not very optimistic about using Apple EarPods for this application. There is a huge amount of placement variability just through the way how deep and how hard you shove them into the ear canal. Small leaks between the pod and the walls of the ear canal make big changes in the frequency response and these vary greatly from person to person and even from placement to placement. So even if there was a set of functions published, it would not be a good fit for a specific person and placement.