I was thinking this is something you could code with Bimmercode. Poking around the net a little bit it looks like this isn't a programmable option. (Maybe I'm wrong, someone will pounce on me immediately if I am)
You can just unplug the connection at the rear exhaust valve while it's closed. Then it won't open up under any conditions. Doesn't throw a code or anything.
Another option is Burger Tuning. They have a module that tunes exactly what you are looking for. Here it is:
https://burgertuning.com/products/ob...e-for-f-series