Natty,
I make most all of my bows from fully quartersawn wood. If you are going to "glue in the reflex"....by gluing a backer onto it there will not be any trouble as long as your form is squared up with the bow. If you are going to heat the self bow either dry heat (heat gun) or steam it make sure that you have the bow stable down it's long axis as well as square to the form.
Because the growth rings are perpedicular to the back and belly ....if the board does "warp" it will go in a lateral direction. That is it will move sideways to the length of the bow. So just to be sure....after you clamp the bow to the form also make sure it is straight along its centerline (tip to tip)
The problem wont be as bad (or non-existant) if the board is kiln-dried, but if it is air cured or partially green pay real close attention. Also if the stave/board is still partially green you can reflex it by simply hanging a full gallon milk jug from its center...while supporting both limb tips and letting dry like that, the farther off the floor with the jug the more the reflex ( it will let the bow blank dry to a natural curve and help get rid of any "propeller twist.....hope that helps
half eye