Airbags IMHO make sense if you have significant load variation, or need/want to alter the ride height for different scenarios. If you do neither of those things, you are best served (again IMHO) to have suitable springs made up to take the weight of your camper/vehicle. Given the "cab forward" design, the front springs on these trucks have a much bigger impact on perceived ride quality than the rear springs, and if you haven't changed those already, its where I would start. Running the right tyres at the right air pressure will also make as much (or more) improvement in the ride as the suspension.
Airbags improving ride is a bit of a misonmer as far as I am concerned. They only improve the ride by being able to adjust the spring rate to suit the load you are carrying, if you get that right to begin with, no real improvement.
I have airbags fitted to my non-Fuso truck because I have a slide on camper, and the vehicle sees more time with the camper off it, than on it (sadly). I have airbag cradles fitted to my truck to ensure articulation isn't an issue. It also helps in preventing failure by over-extension (which is the most common airbag failure mode)
Not my video, but these are the cradles I have fitted.
Ride quality unloaded with 10psi in the bags isn't changed for me because my F250 is softly sprung in the rear, but at maximum GVM with 1.7tonne of camper/food/water/people on board and with 80psi in the bags it provides a substantial improvement, as the suspension would hit the bump stops over just average bumps, and it makes it just as compliant as when the truck is unloaded.
This is the opposite problem that Fuso's have (in my experience). They are sprung to support maximum GVM - but if you have no load/lightly loaded, the spring rates are way too high. So as far as I am concerned, adding airbags to your existing suspension would only make that worse.
