Swamp Thang, I would keep the hi crowned back and keep the belly pretty flat & square. Crepe Myrtle is really elastic and bendy in tension (seems impossible to get a tension failure on the back), but a bit soft in compression, and tends to take some set, if you don't toast the belly good (early in tillering, and then again at the end). I've made a few CM bows and I can tell you that even when you think it's dry, it ain't. I recommend several sessions with the heat gun (if it's dried/seasoned already). Whenever you do your heat corrections and get it clamped down, I'd go ahead and heat the rest of the stave, to match. Be sure to get a weight on the stave, before and after the heat treatments to track the moisture loss. I noticed on every stave I toasted, that a little burst of watery sap would boil out of the spots on the belly where early-wood end grain was exposed. I think Crepe Myrtle is an underused bow wood, and it's everywhere. –John