What I'm interested in seeing is how the larger wheel performs in the small housing.
You'll have less turbine area not being occupied by the blades, so less ex. gas can pass by the blades without hitting them. Now this will obviously make your spool up very quick, but I'm worried about your top end. That's part of the reason people clip the turbine blades, to provide more top end flow. So in theory, if your on the stock diameter IWG, this problem should be even worse for you.
Think of a turbine wheel spinning at exactly the RPM needed to achieve your boost target. Now extra unneeded EGBP previously would have slipped by between the housing and the blades and IWG, but now more is being forced under higher pressure out of the IWG and against the blades of the turbine.