Orion, yep these are tapered just like a field point or whatever.
I also agree, for my purposes I just soon see a straight taper for more weight and strength. Not sure about the leverage stuff, too deep for me. I just beat the stuffin' out of things and see how it works.
PDP is Precision Designed Products, they make all the glue on field points and steel screw in adapters so commonly available. I've been yakking with sou-pawbowhunter about this. He's looking into having a field point ground down to a glue on taper. Now that would be something, all steel and no screw in adapters either!
One thing I've noted, since you are boosting the spine to shoot the heavy points, you are adding strength to the wood shaft. A 70# cedar is stronger than a 50#. Hardwood footing would be stronger still.
Lots of possibilities, I'll be playing with this one for a while yet.