That's sweet! I totally think you should get the 66.56mm Haweka collett with zero taper ---- just to see you still get any variability when balancing / rotating wheel 180*, and balancing again. I mean, you've gotten SO SO SO SO far already, what's another $900? We've literally spent YEARS discussing this topic / thinking about the right strategy ---- and you've pulled the trigger!
For what its worth, I'm not car behind you .... once I get the garaj complete, I'm gettin' my own wheel balancer as well!