SIL modified her Class C by removing the bed in the rear bedroom to accommodate multiple crates (she breeds/shows labs). She used the cab overhead bed for herself and the pull-out sleep sofa if she had extra people with her. Doing this left the bulk of the unit intact and usable. CAVEAT: If you go this route please make sure your rear axle can handle the weight of 4 large dogs plus crates.
I've never used them either.
Our dogs are trained well enough that they wouldn't touch anything. However, when crate training is done properly it serves as a "safe haven" and can be indispensable during thunderstorms, travel times, etc.