I was wondering why we don't have this for our little game. Gyro gunsight certaintly existed before and during WW2.
I believe they are not in the game so that everyone is on the same level playing field when it comes to gunnery and predicting lead.
As far as engine management and all that stuff ... could care less if HT does or does not put it in the game. If it was put in the game it would have to be an option, those who choose to use it should not gain any advantage over those who choose not use it.
You want immersion ... have at it ... but you get nothing special above and beyond what the game already does for us on our behalf.