Tweeter is right here, i don’t think not having the holes will impact it very much, but i could be wrong:
https://www.head-fi.org/threads/1more-h1707-triple-driver-over-ear.849824/page-15#post-14221717
Either way, it’s not going to sound exactly the same as the original pads, but there is no way i’m wearing on-ears. Pads with small openings will sound closer to the original sound than pads with large openings and i think it’s definitely a worthwhile sacrifice if the sound is even affected in a bad way, which I’m not convinced it is.
Edit: also, I’m mostly parroting what Slater already said in the head-fi thread as he seems to have played around with different pads and mods and reached conclusions that most people who tried it seemed to agree with.