Here's how we handle photo-impass with Corona:
First make the lighting in the scene on the 3D model with a black background or whatever (We use HDRI's), match it with what you see in the drone image, angle of lighting ~ strength, etc...
Use a CoronaColorCorrect on the background image (drone) and pull it in the Direct Visibility override in settings (F10-scene)
The only way to get the original drone image rendererd, is to not use any VFB settings. You will use them for sure. Don't forget your BG image is prob 8bit or 12bit (NEF?). In the end you're rendering out 3D that's 16bit+ and some 8/12 bit info in the background.
The highlight compress setting is always the most important factor for us when doing photo-impass cause of (I think) this difference in pixel-depth-info.
Thus the background will be affected faster (harder?) by the highlight compress setting for example and make it look bland, compared to the 3D.
So you really need to tweak that BG with the corona-color-override on top, with the (lighting + refraction + reflection) HDRI untill you get that background aligned with the 3D-model.
That's the way we feel and do it here.. My 5 cents.