I think the hotspot is related to me trying to bend the 400s headband in the past to adjust the pressure around my ears. I bent it back to the normal position and now more clamping force on the earcubs and less pressure on the top of my head. I don’t think I can win or my head just doesn’t like hifiman headphones haha. The old headband on the Hifiman HE-500 does not cause this hot spot, I think the comfort issues probably come from the weight. I might look into getting a ZMF pilot pad to see if this increases the comfort. Thanks again.