I appreciate all of the response on this topic. Please let me approach this from another direction.
Many years ago I worked in Detroit and knew several Ford engineers. If I could, I would ask them this question.
Since the Expy has a class IV hitch that can take 1,000# of tongue weight, is it possible that the 895 is simply a selected number to reduce the risk that a driver might exceed the 4,128# RAGWR? If we can stay under that axle limit and the GVWR with a tongue weight of 1,000 or even 1,050, what item is subject to overstress?
What is the problem with a tongue percentage of 15.5% to 15.8%? Is there any loss of stability with that?
I respect all of the expertise on this listserv. It also is apparent as I look at tow ratings that the vast majority of those towing a Jayco 28BHS are over their vehicle's tongue rating and seem to be doing fine.