Both @TheFlightGuySP and @DerekSP bring great ideas to the table. What I envision is similar to what Derek originally mentioned, being a mechanic that calculates lift by determining angle and speed. Not necessarily in really time or dynamic, but rather just an "opposite drag". In the simplest way I can think of it, calculating the lift would be similar to reversing (but interacting with) the drag that already gets calculated anyway.

@TheFlightGuySP ferram aerodynamics mod in KSP does this I think so it's not unthinkable

@DerekSP Hmm, I see what you mean.
That makes sense.

@TheFlightGuySP yeah exactly but the shape of the fuselage wont change mid-game, so it would boil down to just calculating the same thing as if it was a wing at a specific angle

@DerekSP However, if the fuselage physics were replaced with the stock wing physics, then it probably wouldn't be much different from the performance impact from the regular stock wings.
This wouldn't be incredibly realistic, but it would be easier on devices.

@DerekSP I was thinking along the lines of: the fuselages shape determines its lift, drag, and stall point based on the width and height of the fuselage, and these values would be nonlinear.
In other words: the game would semi-realistically simulate airflow physics of the fuselage parts for lift, drag, and stall point values.

with that said though I am perfectly fine with how things are right now

@TheFlightGuySP would it though, you could just run the calculations once for each fuselage block and just substitute it for a "virtual wing" with an equivalent amount of lift

This is, however, an interesting idea.
This would be great as a mod (though it would be restricted to devices that can handle the calculations).

The calculations needed to find the exact amount of lift and drag from fuselage blocks would have a significant performance impact on devices. It's not really necessary when fuselage blocks can be fitted over the stock wings to form fuselage wings.

Because no.