I have been looking for 25 years Tracy and I haven't either.
I use heat on most bows I build,but to say they are heat treated like is explained in BB or on here to some extent I don't.I just heat them on a form for straighting and adding reflex till as Eddie said they look right and smell very good.
I do use it on most woods but it does seem to help white wood a lot more in my experience.
Pappy