Fail for not reading. I am the owner of the gray 335i. I run jb4 g5 (non iso) and older firmware from 2012. Newer ISO stuff has much better boost control, which would have helped me considering i am 99% sure my cel on the third run came from overboosting, which initiates a limp mode. Automatically puts the car back to stock boost levels until you turn it off/on again. Its a safety precaution.
Second, Post shift timing pull is common on cars that even have a protune. Usually happens going into 4th gear on 6AT vehicles. The only way around it is the bms flatline fix flash that you run in combination with JB4. I've seen the logs of the white 335i this morning, and his timing was half of what it should have been throughout the runs, not just the shift. My car has the flatline timing issue as well, but my timing recovered after my shifts, the white car did not.
Third, the gti really surprised us. I think he would have caught back up and passed me when i shift into 5th gear. Very quick little car indeed. I'd be curious to know its exact weight in the form it came out in (the seats taken out and everything). Prob wouldnt make much of a difference, but every little bit of weight counts i suppose! My 335i is just over 3700 with me in it