Complex engine management would be nice. By manually setting your radiator, prop pitch/RPM, mixture and manifold pressure, you would get better performance than on "auto" setting. Choosing the preferred system should be chosen only from the hangar, not while inflight. Naturally, the planes which in reality had automated systems should have them in AH2 as well. If there was a manual override, that should be available as well. If you abuse your engine, it should overheat and eventually get damaged and loose power.
Yes, I'm looking forward to the upcoming IL2 Forgotten Battles as well.
Camo