twin charging/compound boost 4 cylinders is for dumbys and gumbys
^correct, definitely not tooters and booters
LS1 swap would pass advanced emission testing AND have the ability to be tuned with HP tuners or EFI live rather easily.
Just gotta see how complicated the install would be.
iirc the ecu controls alot of other features on the car. 
This is certainly something I would look into, but I believe most BMW’s use a body control module for that purpose.
Duramax Diesel
Do it