When doing custom window, consider a category for stock aero
I'm exactly wondering how your lift and drag is calculated and displayed
firstly L and D is displayed in acceleration, not forces
secondly when using a propeller-used plane it will misbehave after closing the prop bays, but in a different manner compared to stock AeroGUI
With my Eve SSTO, the stock AeroGUI always show correct lift, when bay open the prop's forward thrust is considered as negitive induced drag but after prop bay closure it shoulds faulty drag, whereas MechJeb Lift&Drag does not count prop (so when prop bay on, still positive drag, by estimation L/D around 6-7 subsonic as expected), but when I closed the bay climbed to 2500m/s@70km it still shows 15m/s^2 lift and 4m/s^2 drag (according to AeroGUI's lift readout lift acc. is not greater than 600mm/s^2) BTW, MJ cannot display L/D, one of the crucial stuff in your flight
Suggestion:
According to the behaviour above, I think the aero display are written by you from scratch
So I hope you can create a Aero data option that is completely unaffected by props, and have L/D readout
And another display item (you can freely choose its category) is to display "effective gravity" - literally is gravity - centriffugal force. Then display your lift-to-weight ratio according to this.
Anyway I think this is very important on stock aero-based craft optimization. As I used stock AeroGUI to optimize my Eve SSTO a lot by using hyperedit cheats to push me into a 16.0km 145m/s level flight with prop bays closed to avoid fake readout, then use AeroGUI to determine my ascent path to always achieve the maximum 4.6 l/d on my Eve SSTO, and finally made that possible.