A correctly inflated pneumatic jockey wheel is fine with a mover and avoids the 'corner dig in' of a flat profile solid wheel on loose or soft surfaces particularly when moving van forward i.e. jockey wheel leading.
The snags are that the pneumatic tyre is generally larger diameter than the solid, and if you have the jockey wheel in the middle of the a frame rather than clamped outside then you may have less ground clearance when it is in the fully retraced position. This can mean grounding particularly on the approach side of speed humps and sometimes on ferries - and even on the very poor road surfaces which are becoming increasingly common.
another nuisance is that some pneumatics are mounted in very wide side pieces and you may find it difficult if not impossible to use a standard car pump with a turn-over locking lever at the top. A bicycle pump will probably be ok but it's one more thing to carry and loose.
there are pneumatic profile solid tyres available, but they are expensive and tend to be narrower than must jockey wheel hubs. another alternative is to fill the tyre with a suitable foam, but at the moment I am having difficulty in finding a soource, so i'm trying the normal builders foam as used for cavity filling. not ideal but it's better than a flat profile wheel.