It's probably not worth hampering Teacups's development as a player if they're only going to bat him at 9 anyway. Better off letting him play PCDIY unless Bibu drops heaps of catches.
I think it's only a matter of time until Teacups comes good. His activity is bound to push him towards the first team soon enough.
Point stands. If he's not going to bat in the top 7 then all you're doing is wasting the opportunity for him to develop properly. It's different for experienced/established players obviously but there's little point dragging up a promising player and giving him a nothing role IMO.