Hi,
maybe i am not on the right track here but, as far as i am understanding things, the effect of gluing in reflex ist (partly) gone when you heat reflex it before gluing up.
When gluing in reflex the back gets compressed, this is the advantage of the perry reflex. You got lots of movement before the back gets into tension again.
With the belly its the same, when gluing in the reflex, the belly gets under tension first. It will not be compressed before the bow is drawn beyond the original shape of the laminates.