If you are looking at tip movement and judging target weight you are looking at the wrong thing. How far is your string hanging down? If you are at 24" and pulling target weight with 1/2" tip movement your bow is still pulling about target weight at 24". Weight is not a function of limb stiffness as much as it is a function of leverage.
That's what I meant but put better
Your string shouldn't 'hang down' it should be tight to the belly. The way the force is applied to the limbs changes a lot with a dangly string - not good. More down than in - this will give you the impression your outer limbs are stiff. Hard to tiller when you aren't seeing the picture correctly. Tiller should be perfect from the outset.