John, yes it is worth fiting a pneumatic jockey wheel with a mover. They do not dig in like the solid ones, are much easier to move a van over grass or gravel surfaces and provide some suspension to the front end. Problems,,,if you dont keep it fully inflated it can roll off the rim, they , like all pneumatic wheels are likely to suffer a puncture at some time, and depending on your A frame clearances, it may not sit as high when retracted.
The main point is they relieve the stress on the mover which has got to be good.