Maybe not the best person
but I have done a lot of software testing, swapping logs & implementing suggestions from Terry & am running the ISO system. Bottom line for the most accurate answer email Terry & send him a log with the problem taking place.
That being said a few just be sure things. What JB4 version do you have, what interface date & what firmware version? Is the JB4 firmware running the 335is specific Maps? What fuel are you using?
Few thing I did about hitting WOT. I blocked the pedal so I don't hit the WOT kick-down switch but still get 100% open throttle. When a situation arises that I have to go to WOT I drive the car like a stick shift & manually shift. Usually a 2 gear down shift will avoid any hesistaion. The JB4 also has a built in "LAG-FIX" that you can dial in to greatly reduce or eliminate the problem.
The thing you really need to do after checking that the basic install & that the software is current is to create some logs of the problem. Will try to answer any questions about the JB4 on the IS that I can.