I have made 2 backed(hickory) bows with boo flooring. Both came out light and with more set than I planned on. Bamboo is stronger than the hickory backing and will cause more stress on the lamboo belly. I would use a more appropriate belly lam for a boo backed bow. If you want to use the lamboo, make it the core and add a compression strong belly wood, like osage, ipe, etc.