Originally Posted by Marki_GSA
Yes I agree it is mostly by adding fuel. The downside of the wide band route is that it doesn't really have much affect outside closed loop simply because the ecu doesn't look at them. Maybe not a problem for yourself and a lot of other riders especially on a big GS that isn't exactly a race bike. For some users though the retune is better if they are on the WOT a lot, generally driving hard. It's all preference and many will scoff saying it's not needed and a waste of time and money, others will see it as life saving and worth every penny/cent.
Actually when you richen the Closed Loop mixture with a wideband controller, it also adjusts the fuel in all Open Loop areas including WOT and Warm-Up through a process called adaptation. The 1150s and 1200s have that for sure and I suspect the 1100 does as well but haven't measured it yet. As an example if you set the wideband lambda to 0.94, WOT gets 6% richer and the warmup gets 6% richer after an adaptation period, I've measured the effect and presented recorded WOT and warmup AFR data.