I guess you could work out the maths and setup a macro to give you the custom FOV you want. You'd have to work out the maths anyway even if there was a quick FOV setting. Id love to be able to switch to my preferred FOV like i could with IL2. But your right it is probably more about gaming the system than creating a simulation as most people dont have a monitor capable of a life size representation. So even "simulating" FOV for a given screen size and seating distance is not going to give you a simulation anyway because the screen sizes are too small. Thats why the zoom FOV exists.
Thats also why later this year Im attempting to build a 65-80" inch surround screen with a high enough resolution that you can create a lifesize cockpit view with good vertical and horizontal FOV. See my other 82" bezel-less thread to see what im talking about!
That's when you ultimately want a single fixed FOV appropriate for your screen and seating distance.