Sunfish...exactly! The issue is benefit. When a PM can splash around 5billion on boondoggles as a skin saving measure this benefit ,in cost terms, is small cheese.
Dick, you refer to the Garmin Perspective suite. Not sure this does the deal. Suggest you talk to a dealer and ask them where it states BARO-VNAV as a selectable approach and where you input the data and where it excludes all other approaches.