I'm not surprised you guys are experiencing good results with the BMS thermostat. I think the key to lower temps is deleting/replacing the stock thermostat.
If I'm not mistaken the key difference between the advan stage 1 and 2 is the larger setrab core and the addition of an lower temp thermostat. I'm not sure if the larger core is necessary, but the thermostat is what's keeping the oil cool.
I think this BMS thermostat is really good value considering what it offers. I think the ultimate mod would be an option to turn it on and off via canbus, but we can't have it all
