If correct, there may be many reasons it's not sold for some specific applications. I did a quick search and found a RideRite model for 2014 F53 chassis. Below is installation instructions.
http://riderite.com/-/media/www/ride...lManual_EN.pdf
The first thing I would check is whether there is enough clearance on either side of the frame to install the air bag assemblies. It's possible that some motorhomes may be built in such a way that it precludes the installation.