As a followup, I spoke to Progressive Industries about the value of an accessable digital readout. They indicated that the display is there for several reasons and that easy visual access is important for each of the reasons.
Trouble shooting is much easier if the owner can read error/fault codes as they occur without having to remove access panels or ports. With respect to getting a clean bill of health from the unit immediately upon plugging in (or by using a standalone circuit tester), that reading is a brief snapshot in immediate time and as more folks arrive and place greater demands on what might be a marginal electrical service system at a given park, the display might well begin to show reflection of changing conditions that are not desirable as things are changing rather than later on when the only option for voltage dropping below 104 volts, for example, is a total shutdown.
I have mixed thoughts about where the remote dispkay should be mounted for best use under most potential need scenarios. Outside the coach but on the wall of the power side storage area makes sense for plugging in and getting an immediate diagnosis. Inside the coach would be good for monitoring changing conditions. Maybe that is why Progressive Industries offers an additional digital display.
But, wherever the display is placed, I would like to be able to check on it without having to remove panels.