Longtime ago, I discuss with european bowyer about use of billet in warbow. It was of concern that the very center of bow will have maximum stress, so conventional splice of 3~4 inch will have higher chance to break than longer splice. He thought that if made quite long, 6~10 inch it would allow glue joint to bend than hinge as shorter splice might do. Also he suggest backing of some sort to prevent lift of the fiber. I have 2 billet sets I would like to try with, just need some backing for them.
Im sure it work when done right. Composite bow is having several splices in the core and in most designs these splices are require to bend, though they do have sinew backing, Im sure it will work.