You guys are all talking about global analysis (“Quality Checker”), which this is not about.
I am refering to local measurements of a single surface pair.
This is used to refine surfaces manually. For example in gap construction or featureline (“crease”) building. Also establishing constant and even angles in surface transitions is key to even light flow and avoiding local shadows.
Creases also need a minimum angle . If the the angle gets too small, they might not be visible depending on the manufacturing method and material.
Please dont mix these tools up.
This was explained in depth here: CLICK