If it matters, BM3 is developing a board that will allow for flex fuel sensors and selectable map switching. Imagine being able to mix some E30, select the map and go. Need to fill up at some unknown station? Throw some 93 in there, switch maps and off you go. With sensors installed, you can even mix on the fly and the flex fuel sensor will adjust the tune for you!
https://www.protuningfreaks.com/blogs/news/tagged/bmw