Osage is so unique that one can make all kinds of claims, and you wouldn't know if it's the wood's properties that makes a great bow or the bowyer, or both. It can be tortured with steam and heat, repeatedly in some instances. It'll take more abuse than any wood I can think of. So when I see claims of great bows being made from this wood guys, well, you're kinda talking to the choir here.
Personally, I don't like hot boxes or hot attics for speed drying this particular wood. And I don't see any need for steam for this gentleman's stave unless he's looking to recurve. His only concern at this point should be to get his stave reduced for faster drying, which reduces the risk of drying checks also. Do this, and in a month or two, he can do some heat tempering if he likes, flipping tips or make any needed corrections using a heat gun.........Art B