I would think that would work. But it really depends on the grain of the purpleheart, and the poundage that you make the bow.
My last one I made was 65" 50# at 28".
Shot beautiful, but started fretting on the belly where the grain ran through from back to belly.
Of course that bow was only 1 1/2" wide at the fades, with a straight taper to 1/2 inch tips, so it was fairly heavily stressed.