Sorry for saying so, but i don't think you'll get this feature because it already is in the sim
There is CEM on and CEM off and there are all sorts of on-screen messages telling the player exactly what's broken in the engine. CEM is in fact pretty forgiving at this stage and it's very easy to learn it.
To properly train people in engine operation with CEM on, the easiest way is to start with the simpler engines: low number of controls and a fixed pitch prop.
In other words, a Tiger Moth. There's a reason it was included in the sim and it's exactly that: it's supposed to be difficult to manage the engine at full difficulty settings, so we have a trainer to practice on.
If i had to train someone, i would start from the simpler stuff and go towards the more complicated ones. In terms of engine operation this would mean:
Fixed pitch prop and no radiators: A couple of flights in the Tiger Moth.
Two-position prop with water radiator: A few flights in the Hurricane with the DeHavilland prop.
Constant speed prop with water radiator: A couple of flights in the Rotol Hurricane.
Manual pitch prop with water and oil radiator: A few flights in the 109
Advanced course: Air-cooled radial engines (G.50 and Blenheim) and twin-engined aircraft.
If i didn't want to do it or my recruits didn't want to listen, i would set the difficulty settings lower, problem solved.
You can do this right now in fact: enable the CEM to train your guys in boost/RPM handling but disable temperature effects to stop them from overheating. Once they are comfortable with it, enable temp effects too.
Everything you need is already in the sim, there's even a "look at instruments" snap-view command for checking the most vital gauges while in flight and it momentarily overrides all other view controls for as long as you keep the button pressed: i can look around with freetrack, press it for a second to take a look at my temperature gauge, release it and the view will go back to where i was looking at.