There appears to be an inconsistency in the PNA help file. The page for CalManager.CreateCustomCal() method seems to indicate that it should be used to return a SMC or VMC calibration object whereas the page for CreateCustomCalEx() method seems to indicate it returns an IGuidedCalibration from which you can get NoiseCal, GainCompressionCal or SweptIMDCal objects through the IGuidedCalibration.CustomCalConfiguration() method.
The inconsistency is that the examples for VMC all show using CreateCustomCalEx() and IGuidedCalibration.CustomCalConfiguration() to get the VMC object. Does that work and is just not documented in the methods? Or is that incorrect?