Agreed.
You are spot on in regard to owner manual being near useless. The manuals are often produced to cover everything they sell, from pickup campers to 5th wheels, of every option configuration imaginable. Could ask the service department where I purchased the trailer, but they will likely only be taking an educated guess as well. The only outside port is for Satellite connection and clearly marked Satellite Ready. The line setting sheet lists the already installed solar system, but nothing regarding being wired for additional PV. Makes sense to me that they might have additional wiring for another PV, but there is already wiring going from the controller to the battery bank. Even if adding more panels, why would you need additional wire going to the battery bank? I'm not losing any sleep over this issue, but I like to understand how and why things work.
Regardless, I appreciate your input.