Headphone Calibration: E.A.R.S., DRCDesigner and FIR Designer

[bonzothecat]

Kind of went down a rabbit hole seeking to find a semi-automated way to calibrate my headphones with EARS. I know there are all kinds of issues EARS and headphone measurement, but I am old and unable to hear past 12khz and that seems to be where EARS falls apart and I only have over-ear cans. At any rate, I started with DRCDesigner Digital Room Correction Designer Help (alanjordan.org) and was able to reverse engineer his work into 3 batch files: 1) enumerate audio devices 2) run sweeps on both channels on EARS (given parameters from 1) 3) Generate a stereo FIR filter in wav format. I started with Harman curve, but decided it was not for me, so I cut every db in half (perhaps a new standard half harman?) which sounded better to me. I calibrated 6 headphones with this method, but in the end, I did not like the artifacts that DRC was introducing, so moved on to FIR Designer FIR DESIGNER - Audio FIR filter design tool for speakers | Eclipse Audio and REW and was much happier with the FIR filters it generated over DRC.
I had another thought today which seems to be working out. I am calibrating my headphones to a flat response and then generating a second FIR filter that goes from a flat response to B&K 1974 and the half harman. I then use two convolution filters in roon - one to get to a flat response a second to get to a target which enables me to try out different targets without having to recalibrate the headphone. I have tried the process on HifiMan Sundara and DT770 Pro and it sounds pretty good with both.
At any rate - is there anything fundamentally wrong with this approach?
Also if anyone wants a crack at DRCDesigner, I am happy to share my batch files....