I did a sinew-backed bow using quartersawn osage, it was fine. Personally I think this orientation might make better bows due to the fact that there is no weak spring wood being mashed down. The key is to get the continuous fibers on the back, I think that is what is particularly difficult with osage, because of its tendency to grow crooked and its pin knots. Probably why you don't see osage backing strips being used much. I do think you could make a fairly long bow, something with a modest design that doesn't have a hard bend, and get away with some runout. Possibly use billets and evaluate them closely for grain before using.