I can say that I have heard too much 1 khz in Hifimans as well, some on the same level as Audeze, some - a bit less. One of the reasons is 2-3 khz dip, just like you said in your post (dips always make frequencies before and after it appear to be hotter), the other is evenly descending FR from 1 khz towards bass, which makes 1 khz being a peak.

I guess that open-backed Focals are more comfortable in terms of sound signature than other hi-fi headphones.