Keep in mind the print calls -A- as the primary datum. That means that it has to be the leveling feature datum. If we measure and level the top of the sheet metal then measure the hole and datum, we are using the plane vector with the circle centroid as the level primary. I suggest this is a better way to accomplish the measurement myself, however, that's not to the print. It implies using the axis of -A- and that doesn't mean to use the reference top plane. I can scan two circles with 30,000pts each to create a cylinder with my Zeiss VAST scanning head and create the turn space level in UMess. I just don't think its too practical with a touch trigger system when you can accomplish almost the same thing by making the plane your primary datum.