I did this swap on a 2005 LGT Wagon.
I kept the twin scroll turbo up setup.
I did not wire up the extra AVCS.
My tune is not great and needs more work.
In CA the biggest issue it smog. They are starting to check the tunes. I will probably have to put a stock tune back on the car for SMOG and it will throw a code that I need to revert more back to stock.
Due to smog, I wouldn't have done it. If the smog was not an issue, with a proper tune, it works fine.