Ryan, I've worked a lot with vine maple and can tell you that it's a waste of time to try to heat correct such a stave until the tension has been worked out - it will just return to it's original shape. Vine maple often grows under severe tension, so much so that NW loggers treat this stuff with respect when clearing an area as it can rear back and injure you when that tension is suddently released. When you harvest such wood all that stress is relieved and it begins to curl up. This effect becomes more pronounced as the stave dries. My theory is that the tension wood contracts when stress is relieved and the wood dries. What I have found is that you need to work this tension out of the wood by essentially stretching it during the tillering process. Some here are going to say that in doing so you are inducing set into the wood. I don't believe that to be the case here as this has nothing to do with the compression wood. Either way, it's simply not feasbile to tiller a stave that maintains 6+ inches of reflex, and my experience is that you cannot heat it out.
BTW, I have never experienced this effect with any wood other than vine maple - it trully seems to be unique in this regard.