100% stock. I have one of the few high HP stock M3s. I think I'm the 3 highest HP for stock car with 91oct on Pencil Geeks Dyno Chart. My dad will almost every Dinan bolt on and tune including Dinan full race exhaust, he only dyno'd at like 387, same dyno same day. A bit confusing but maybe he started out way low, like 320's to start...
As far as the custom wiring for engine speed, the valves take about 5 seconds to fully open or close, at lease mine do. So having them pop open when you floor the car wont work. The issue with the M button concept is also that its not just open or closed, so you would have to have a timer run for about 5 seconds when you press the button. But they close/open faster and slower sometimes, so it could cause burnout on the valve.