With the slightly re-designed front bath on the mid 2017 (2018 model year) Newports, we as well as another HL member who happens to be a HVAC contractor, had a discussion about getting airflow into the front closets.
The heat generated through the front cap, especially on the black painted caps was quite high.
Andy W. - back from vacation and following this ????????????????????
The duct work and ceiling insulation has changed again too, although I don't know when. It is conventional style work now, e.g. insulated aluminized ducts ((I think) and batt type insulation.
The air flow and heat concerns is what drove us towards a paint option of the dark grey over the black highlighted options.