To me, rotation keeps the film uniform as it solidifies. Never seen gloves made this way. Spraying a hand shaped mandrel and plain dipping are the only processes I knew. Some are made right/ left in one of three or 4 sizes. Surgical types are the most consistent in thickness; and are sprayed. Thin gloves are made about three inches longer than finished product, to roll the band on opening end.
I find HF's work gloves are reasonable, satisfactory, and dispense easily, bulked packed and fit either right or left.