To be candid about this, around a decade ago I really didn't like HRWs, at least in the bridge position in solid bodies. The high frequency output was too sharp to my ears. Eventually I sorted it out. The neck position was always fine. It's odd to me because I've never had an issue with Schallers.
I'm pretty sure HRWs were cryo treated. I asked Ren once. He just smiled. In that particular context it would have been easy for him to say something like there's more to the story. He didn't. This conversation occured when I brought in a Johnny Smith with a Floating #3 pickup and asked about getting a tone control added. He did the work while I was there, which took maybe 15-20 minutes. He charged very little, no more than $50.