I have really been studying this subject lately. I am a student of bow design and performance and most of what I know has come from others on this site and others, so hopefully some of the experts will answer the question with a more scientific and complete answer. Even if the bow has as much as 4" to 4-1/2" of reflex unstrung, you can often tiller the limb by changing the thickness and width profiles to bend the way you want it through the draw. I am learning that just enough visible reflex at brace to provide stiff tips and a low string angle at full draw will provide better cast. More than this can be difficult to string and may be unstable. My test bows are showing me that one to two inches of reflex after tillering provides good performance and good behavior. Deflex is also a factor... the more deflex you induce, the more reflex it takes to counteract it and keep good performance. Jim