"Under vagueness doctrine, a statute is also void for vagueness if a legislature's delegation of authority to judges and/or administrators is so extensive that it would lead to arbitrary prosecutions."
AMA needs to argue this, not only do we not know if we are breaking the law, how can a cop know? The things I mentioned above would come into play, as would relative position. I want to follow the law, I do, but I have no way to follow it other than the "eyeball" method. My eyeball is different than yours, and a LEOs.
I suppose a range finder could work but I doubt an LEO is going to know how to apply the trigonometry to figure it out.
Now of course in extreme circumstances, when an rc aircraft nearly collides with an airliner at 5000 feet that is a different story.
Would cops bother us? Go watch you tube. You will get your answer there. Not to mention that 100s of FOGs/pencil ducks at our own clubs that just sit around causing issues is more what I am worried about.