I've been running with an LC-1 and BoosterPlug, kind of a belt and suspenders approach. The LC-1 for Closed Loop and the BoosterPlug for Open Loop. For some time I have wanted to see how the LC-1 and Motronic performed without the BP shifting the stock Open Loop AFR tables 6% richer because I know that Adaptation Values get built from Closed Loop and get applied to Open Loop. Confirming it worked that way would mean that the BoosterPlug was a nice-to-have (since I own one), not a need-to-have.
A key to these tests is a cold start, watching how the Motronic and LC-1 transition from cold (enriched and Open Loop) to warm (no afterstart or warmup enrichments, and Closed Loop). Therefore both tests were begun immediately after start and on the same course. (Note: In the upper chart, second half, I was modulating the throttle more than in the second half of the bottom chart. Otherwise, they are for the same course.)
I got out for the first two of several rides. In the attached photo, you can see the first ride (top chart) after the Motronic is reset with no BP, and then a day later, the second ride. In the first ride after reset (in my theory, before the Adaptation Values referred to in the BMW Service manual can be rebuilt) you can see a lot of deviations from 13.8:1. If you look carefully on the left of the top chart you can see the mixture starting at about 12:1 and then watch what happens while the bike warms up at about the 3 minute mark (same point below). You can also see the histogram on the right, it being the distribution of all AFRs during the ride.
In the below chart, second ride from a cold start, you can see better adherence to 13.8 and a tighter histogram. (Ignore the spikes that go to the top of the chart, they are Overrun Fuel Cutoff.) It also gets to 13.8 right away, before the bike has warmed up and before it can be in Closed Loop, in the first minute or so. (Notice the dips to lower AFRs, that's where I'm shifting!) The only surprise in the lower chart is the blip to 14.7:1 (Open Loop target AFR of the reset Motronic) between 1:40 and 3:20 minutes. This was after a stop sign and reacceleration, before CL had started and perhaps (my deduction) in an area of the Adaptation Values table that had not built sufficient data yet.
I plan to make many more rides and watch this closely and will have some more data over the coming weeks.
In the photo, there are two horizonal dotted lines. The top line is 14.7:1 (Open Loop Table before Adaptation) and the bottom line is at 13.8:1 (My AFR target set by the LC-1).