I'll tell you something: I've more then 5 customers running on a fury écu on a s54 engine with dual vanos. Vanos always active, even on idle. Afr spot on, nice flat torque curve between 365-400 nm and 365-410 hp (some stock engines, some build with 302/296 cams ect) all on 1 fuel map strategy. Your vvt maps decide the position off your cams, so if load axis of vvt and fuel map are the same, there is definitely not a need for a second fuel map. As you have a m50 with a simply on-off vanos, thing getting even more straight forward. You're making it yourself way to hard.
Have done m52b25tu