Unless u want your car to be a full track car...Unless you are willing to spend more on the internal part (upgrade to performance part), go for average turbo setting for reliability..
i think the preve engine and turbo at its limit...try put bigger turbo may blow ur engine..maybe u can put better ecu management or better exhaust flow..ie 2.5 inch or throw away ur catalyc converter...hehehe..(not friendly environment)