At the moment it’s only useful for showing any measured differences between the GRAS KB5000 anthropometric ear and my own pinna. I’ve done this already a few times on a number of headphones, and apart from some concha occlusion issues (where the physical microphone may interfere with frequencies around 8khz), I was surprised at how similar the results were. It kind of just goes to show that while the prevailing notion of “we all have different ears” may be true, this doesn’t show as much variance for frequency response as we may think. The pinna is only one part of the overall ‘ear gain’, so it’s entirely possible that more significant variation exists within the ear canal - but remember that the brain normalizes gain factors regardless, and so in all likelihood we actually do hear things similarly despite having different ears.
At the very least, whatever differences that do exist from having different physical ears is most likely not significant enough to override the brain’s normalization of the gain effects imparted by them.