Stock, our oil coolers are run at a certain(higher) temperature point. The BMS thermostat mod allows the oil coolers to run 24/7 thus being proactive and not reactive to heating. I drive my car very hard, and for long sessions. I am FBO + Software. Adding a FMIC does help with the heat-soak but more so in recovery time, it does not eliminate it by any means!(I too was expecting some miracle temp drop just from a upgraded FMIC) I did not see a large decrease in temperature until I had the thermostat installed/ coupled with FMIC. My temps now NEVER go above 240*F at it's highest/ worst! Also, keep in mind it is 90-95* in FL right now. Stock after 1-2 hard pulls, the gauge would creep over 250*F, and that is while completely STOCK! The hottest my temps go now is 240*F and that's after as many pulls as you want! This picture was after a 20 mile highway run w/ two bikes @ < 110MPH-155MPH.
I am convinced at this point, unless you simply can not drive/ operate the mechanics properly, my car will not overheat. I used to hate the N54 due to it's guaranteed heat soak, but once you solve that problem. You will never be happier in another car, especially on these little, and oh-so precise chassis.