Alan, you and RambleJ are my goto guys when it comes to tunes. He has a similar opinion to yours on the BMS tune. He was talking to me about a company in CA (forget the name) that reflashes the ECU but you have to send it to them.
2015 M3 - Mineral White, Sonoma, Exec, LED, Adaptive Suspension, HK, 19" Light Alloy, 6MT ED 7/7/15 - Adrian
2013 535i - Space Grey, Biege, M-SPort, Premium, Tech, Cold Weather, Luxury Seating, PDC, 6MT ED-10/11/2012 - PCD - Greg Poland