IMO learning on an offset really forces you to learn the basics of fire control.
Yeah sure cheap ones suck at keeping even temps but having to actually build a fire and keep it stoked, whether with charcoal or wood, can go a long way in learning technique. Don't get me wrong, Minion method is great, but there is just something primal about building a fire and having to keep up with it.
A UDS just seems too easy for a beginner. No problem with starting out with one though!!
He just might have trouble if he moves on to something like a Lang 48 or similar with never having actually learning good fire control.