I have a 2021 M340i with 46k miles and the car recently developed this smoking issue only happens in heavy traffic or coming to a stop light on occasion. This does not occur every time and the car is completely fine under spirted driving with no smoke under acceleration or deceleration. Also there is 0 smoke at idle or upon startup. Car is Femto unlocked running MHD e40 tune with a catless downpipe for the past 6k miles. I installed a pcv catch can in hopes if it was a pcv related issue like the gen 1 b58 cars experienced. Catch can caught nothing and the issue is still apparent. My only other guess is that the turbo is starting to go? Oil consumption is quite bad now getting about 300-500 miles per qt of engine oil.
Video:
https://vimeo.com/920783750