I use same kind of set up but with generator. Problem is for company drivers its too complicated. You would be surprised. They need something installed. That they cant mess with.
Why not use better or more batteries? I heard you can have a battery custom built litium ion battery like a cell phone but alot bigger. They are expensive but work the best. I would think it would be better in cost then tri pac apu. Just a thought.
Cant you use a small gas generator and just plug it into your shore power outlet? I took my truck home and plugged it in to an outdoor outlet, turned on the Park Smart and it ran forever, Im thinking a portable generator ought to provide the same.
I have a 2016 with 200k miles my parksmart quit I have no a/c. Gotta get it checked out when I have time it's under warranty. New ones still have issues too.
There are a couple of easy checks you can do, first if you haven't already check that Megafuse that runs the PS, also, do a load test on your PS batteries, even thou it is a 2016 I have heard of cell dead batts.
It depends on which side of the fence you are on, IF you are a driver, yes the diesel apu in most cases is superior, however, if you are a fleet owner, and you are dealing with drivers that can not seem to check things on a regular basis like engine oil in apu, change air filters etc, then the electric system is better,