This article has demonstrated the capability of ZEMAX to evaluate optical performance at intermediate surface locations.  You must be careful in interpreting the results of analyses performed at intermediate surfaces, always keeping in mind the assumptions that ZEMAX uses for such evaluations.  One important assumption made for focal mode optical systems is that many analysis features only make sense if the intermediate surface is at a focus.  These analysis features apply a paraxial marginal ray height solve to locate the intermediate surface at paraxial focus.