I have an interest in working in some of those "super steels" -- I have a friend who's tight in the restaurant scene locally, and we've been talking about high-end, bespoke kitchen knives -- and am filled with dread over the heat treatment.
I was relieved to find a vendor that accepts "onesy-twosey" HT work from individuals -- presumably, they take it and hold it until they have a full batch, then fill their oven.
They also do cryo, which superficially sounded like hokum, but after a bit of research, does seem to add some desirable qualities.
Oh, and I really like working with A2, the HT doesn't intimidate me at all, and I love the edge it holds. But it rusts.