So when I called for 700 rpm idle, it didn't happen. There is a brick wall at 800 rpm which I don't quite understand.... So I guess 800 rpm is all I get (a whopping 25 rpm lower), still it does definitely sound lower.
Also finally played with making a mileage tune... Well... I've been wanting to do it for awhile, but just haven't found a good approach to get more mileage out of the Cruze. I believe I finally found a good approach, and the results are extremely promising thus far. It's an insanely intricate tune, so I won't be sharing the details (its all possible by my cax though, which I do share). You can also really hear the difference when accelerating around 1200 to 2400 rpm in 5th gear, it's a much lower tone growl since its burning more efficiently. It's also much quieter when driving, and uses less boost (indirect result).