Very interesting indeed, reminds me of the modified wheels that people used to put on eclipses. If it works anything like them then it increases peak boost but also delays spool up a bit as the new larger compressor is now larger relative to the turbine. But looks like they do something to the turbine wheel to maybe help with the slower spool up?
Though I did not know the place, I set out for the land of my dreams.
Having arrived at the land of my dreams, I found I did not know the place.