Your going to have to taper some. Even with a pure pyramid design. If it was me, I would start my taper right after the fades. That way, you can always go back and take some of the material out of the fades area to get it bending into the fades some. But if you take it out now, you might not have that option later.
Last one I put together, I tapered right after teh fades from 5/8" to 1/2" at the tips. In the end, I had thier wierd transition at the fades that worked but didn't look nice. If I had it to do over, I would have worked the fades into into the limbs gracefully so it would have smooth lines but would have kept a stiff handle.