I am totally with you on what you feel is OK. While there is a limit in overall weight, there is also limits in pin weight too. Fifth wheel owners tend to load those big front bays up pretty deep sometime, I know I do with mine.
It also depends on what you carry in the truck, and likely on your choice of tire and wheel size too.
Having said all that, there are those that run fully loaded, I doubt you should worry about the truck longevity. It's your comfort level coming down a steep winding road, and going up it too. Having a rig with disc brakes would likely help too.
I see you have a rear kitchen. No doubt there are many somewhat a bit lighter than Arctic Fox, but you do fulltime in it, so you want quality build and insulation too.
Mike
2012 Winnebago Impulse Silver 26QP
2005 16.6 Double Eagle
2018 Jeep Wrangler JK
previously Snowbird Campers,
Triple E Motorhome and Fifth Wheel