Does that really make sense? Unlike a single static image, a video is not one thing. It might go rapidly between invertible and non-invertible. Would you expect it to switch strategies potentially every scene or second...?
Yes it indeed has very specific use case of tutorial videos with white background; those generally stay the same until the switch to dark mode for showing code. It would be impressive if the add-on is smart enough to do what you said to maintain dark background throughout (I don't have a lot of idea of how technically challenging this might be).