Ari, yew and osage have been made into very nice bows before glass, that was with self bows.in glass laminated bows,the performance does not rely entirely on the wood core.Take a look at the high end limbs nowadays and they are made of foam and carbon cores and glass .the foam cores work with laminated bows but i doubt if they can be made into self bows.talking about yew and osage for use in self bows is one thing,yew and osage for laminated glass bows,they are entirely different beings altogether.