a lot of the normal 28" draw info comes from modern recurves. with the deep riser it pushes the back of the bow further from your hand increasing the draw length. the power stroke still remains the same because it only comes from the palm of your hand to your anchor which wont change much, except for wrist angle. im 27 on a glass recurve with a high wrist and full back tension at anchor. on a primitive flat dbow that'll drop to 25. im 5' 8". i think body width and strength also comes into play. on heavy bows form tends to fail a bit and we allow our chest cavity to collapse. honestly measure your draw with a 65 lb then do it with a 30 lber and you will gain some with the light bow. i can throw hundred lb kettlebells around all day but only hunt with a 45-50 lb bow. its effective, allows me to hit full draw, and even after sitting in 0 degree weather for hours or working i can still hit anchor. peace