I'm with Pappy on his advice Lee even thickness taper and bend throughout the tillering process. I'm a slow bow builder on any wood but
when working bl I really go slow. I tiller it out increasing draw length slowly over the course of days spending more time checking taper
thickness often and keeping in the hot box between sessions. I don't heat treat to deep on locust myself, depends on the stave, but have
had some good results with moderate heating on locust.
i also think black locust quality can vary from tree to tree. some really good, some not but the wood will let you know as you work it.
Hope this helps but keep in mind I'm no expert. Good luck, bl makes a great bow when it all comes together.
Greg