Awesome in-depth review as always! Haven't heard the V2 but from your review it seems that everything's been vastly improved except for tonality and I also agree that for a lot of eq-shunning audiophiles tonality is king..
HEDD V1 was spot on for me tonality wise especially because of its similarity to the Hifiman Susvara:
With notable differences being the 6k cavern, which can bother some, and the 15k+ brightness which is not nice for young people.
It seems to me that for people with strong necks and small heads the V2 might be a sidegrade not an upgrade, but I'll have to listen to V2 myself at some point to confirm
Yeah if there's one thing I could never complain about with HEDD1, it's the tonality.