Just saw this post regarding tongue wt and WD hitches. When I purchased my 165 a couple years ago, I contacted Jayco regarding use of a WDH. Their response was "since the tongue wt is only 420 lbs, I shouldn't need one but if I did use one, not to go over an 800lb rated WDH".
I pointed out to them that 420 was a dry weight and with battery and propane it was closer to 600lbs. Thought it kind of odd that they wouldn't recognize that.
Been using a 600lb WDH for a couple of years now with no problem. With my Nissan Frontier I would not want to tow without the weight distribution.
2012 Jayco 165
2011 Nissan Frontier