Leaf reduction on a Star Magnolia

I have a wonderful star magnolia but the leaves are a little large for my liking. Do they respond well to leaf reduction and when is the best time?

I have seen some nice bonsai, but they all have been large bonsai which leads me to believe that the leaves do not reduce by much. I assume you are trying to grow this inside. If so, that will make it even more difficult to get leaves to reduce.