Not to be difficult, but wasn't one of the reasons the calculations in MSA 3 were changed was to remove the part specs from GR&R? If so, wouldn't performing a few GR&Rs on the most typical CMM measurements be acceptable? Perform a GR&R on length in each axis, diameter, and true position should cover the vast majority of CMM work. I offered this to a SQE and he accepted it.
Just a thought, I'm probably wrong, but it worked for my customer.