MHD's programming only allows "exhaust flap always open in sport mode" AFAIK.
Using coding, you can also control the exhaust flap. I read up on coding some time ago, but never implemented anything. Your best bet is to do some research and specifically go into the coding technical forum for coding-related questions:
https://f30.bimmerpost.com/forums/fo...play.php?f=429
From what i recall, you either code it always open or always closed, i am not sure you can do more refined control than that.
Also, I am pretty sure my exhaust flap always opens for the first ~60 seconds on a cold start? So i am a little surprised yours doesn't.