We now build a caster jack especially for our multifunction unit (Bakers Scaffold). This jack fits between the end ladder frame and or outrigger and the caster. They allow adjustment for slightly greater overall height but are indispensable when working on uneven surfaces or even slightly uneven surfaces.
How about using them on stair steps? Until now using a multifunction unit on stairs meant that the unit was never perfectly level unless you are very lucky and the step was exactly on the 2 inch adjustment level.
We invented these. Patent pending.