Dan - on the range rover L322 airbag it is more like a lorry airbag, the top and bottom are like a platform, the bottom is retained with a screw that fits into a lug, for this I will just enlarge the hole in the bottom spring platform, I will cut the lug shorter so it doesn't hit the axle, and I may make a circular metal plate to spread the load on the piston.
The top of the airbag is held in with an R clip round the lug that sticks out the top. So I could just enlarge the bolt hole that the bump stop bolts to to 29mm, put the lug through and then fit the r clip.
Unfortunately the airbag is slightly too tall, if I did this it would be at minimum height, but luckily the distance from minimum to ride height is about the same as the depth taken up by the dish part that holds the bump stop.
So if I can remove that, I can add a flat metal plate for the top of the airbag to sit against, and use the r clip to retain it.
That's the plan anyway.
As for air bags splitting, I suppose they could but I would just do the same as when I change a lorry airbag, kink or block the pipe to the leaking airbag, and inflate the other one to a higher pressure. You would still have the front suspension holding you level, and also your anti roll bars would help keep level as well. The advantage over a coil spring is that to change an airbag is much easier, you don't need a jack or a spring compressor. You just let the truck to minimum height, block the air pipe and remove the retaining fixings. Inflate the other airbag. Change the spring. Put a bit of air in it to get it in the mounts. Put your retaining clips on. Then let it back down and reconnect your air pipe.
Bet you change just as many coil and leaf springs at work as airbags, we certainly do anyway.
It's not for everyone though, I think for serious off roading you would be much better off with coil springs as they are simpler, and you would either fit a spring to cope with either fully loaded (like for an expedition) or completely empty (like a punch challenge truck).
If I wanted to level the truck because I wanted to be able to tow and also have the back of the truck full of heavy gear, I think the spring assistor airbags would be the answer.
But for me I want airbags so you can raise or lower the ride height, and adjust the pressure to cope with heavy or light loads, easy to carry spare becuse they are smaller and lighter than coil springs, also you get on board air tank which you can use to do your tyre pressures (ideal for drifting), but mostly because I like the idea of it!