it depends a bit on the noseweight of the van, as this is what the jockey wheel is carrying. in my expereince pneumatic tyred wheels are the best as the shoulders of the wheel are rounded whereas most 'solid' wheels are square and sharp and dig in especially in loose surfaces. Unfortunately, again in my experience, pneumatic tyres loose their pressure quick rapidly especially in full sun e.g. Spain where I have had a jockey wheel tyre actually explode. I have tried replacing the pneumatic with a solid rubber intended for industrial sack trucks etic, but thesess are of narrower section and tend to come off the rim.
A no win situation. If you can move the van such that the jockey is trailing rather than leading this will help, but obviously difficult to achieve in both directions. Another idea I have yet to sell to the other person involved is to get the other half to get in the van and go to the back, thus reducing the noseweight on the wheel by ???? kg. (and it will be a brave man who asks) but assuming a twin axle noseweight is around 100 kg. then it should be down to ----- around 20 ?? Don't blame me but let us all know if it works.