Some shops will say adjustable sleeves aren't for RV's. Actually, catalogs don't list them for RV's and Box Trucks. They don't have the locating/indexing key that fixed ones do, and the worry is they'll work loose.
This from the folks at Henderson's Line Up in Grants Pass OR. If the parts are assembled clean and grease/oil free, and the pinch bolt is properly torqued, those adjustable bushings WILL stay in place. The torque spec for that bolt is pretty high for the size of the bolt, 65-70 ft-lb if I remember. The instruction sheet tells you.
Henderson repeats the Caster spec Harvard quoted, zero Camber, just a little positive toe, say 1/8" toe-in.