String bridges or not, that sucker is going to flipflop over and over again. There is not enough lateral limb stiffness imo.
see hungarian horn bows: very long reflexed levers, broad limbs. Levers have lateral bone plates for extra stiffness for a good reason.
Tried such extremely long setback levers out on pvc bows some years ago, and quickly learned what not to do.
But hey, I'd like to be proven wrong