Got ya. Still, just like Razor told me, the stft should be around 3-7% from 0. E10 to E40 is about 18% off the base stock tune. I'm seeing upto -17 to -21% at some RPMs on my car right now, so i can't say much,'lol. But I'm only it danger of having TOO MUCH fuel, not "not enough fuel".
Your going like the tune. Not sure how cobbs tune is, or Randy's ( Randy once posted on another forum that did wasn't sure E30 was making much difference to be worth it. High sight is 20/20, but knowing what we know now, its more than worth it, its likely the biggest difference you can make without changing the turbocharger.).
I'd point you toward Panda or freektune. I'm sure cobb can handle it, as Randy can too. The thing is.... Fuel wise, its like 1 change that takes like 20seconds in the software, then your fuel is calibrated. But how that fuel is used, how aggressively its used, and how much you gain from it may vary. For instance. On a stock turbo unit, I made 354ft of torque at 29.5 psi at 2850rpm on E40. Your prob not gonna get that tune, lol, but who will ? Would you even want it ? ( I hate driving on the stock peaky turbo ).
Keep everyone updated if you can, with logs and V-dynos