I would think shaping with heat. I never like to have a bend in the handle bend to much. It’s usually the last place I get working. Seems like if it was shaped with set it would already be bending to much.
Just my 2cent worth. But I was always thinking that the deflexed handle was t make a shorter bow with a longer draw. The reflex to give so early string tension. That’s just my guess though.
Bjrogg