The correction to an engine miss should start with troubleshooting for out of 'spec' air, fuel or spark supply. And, other troubleshooting such as vacuum leaks, loss of compression etc.
Correcting a rough idle condition by adjusting anything to an out of spec setting is a band-aid and/or dangerous. It goes without saying that certainly holds true if it is experimenting rather than following a BMW procedure to remedy a cold miss.
I don't think messing with the Valvetronic system is the way to correct your problem.
https://www.youtube.com/watch?v=qZ9k4Ohssu8