I agree that hot treble is hard to fix well. I hope burn-in will help indeed, but it won't do wonders. It also might be a driver made on Monday... if it was a tweeter, I'd say you'd need to get it re-coated. Actually, some thin coating on the dome would probably improve the treble (and not only that), but it's not an option for consumers.
Maybe you could try exchanging it for another unit that you select from a number of samples (you can probably do it at your dealer). However, I would consider all amps you mentioned bright...
As an alternative, you could use aftermarket pads, with different dust cloth that takes the edge out, but it's a kludge.
If you have the possibility, listen to a later D7200 with your Hugo 2, it might be a great match. At least it's guaranteed it won't have a hot treble
. Which is one reason why I like my modded D7200 more than the D9200, and also why the D7200 mods won't work/make sense on the D9200 (but I don't yet know the true potential of the D9200 drivers).