A couple of years ago, I flew the Air2S with 1/4" long screws attached to the sticks. For slow speed flights shooting video, it seemed a bit easier to make smooth control movements. For more dynamic flying, it wasn't as handy. It's a matter of...
Did you read the part of him wanting to do this for profit?
Did you read the subsequent discussion of what may happen when someone calls in a complaint?
You are attempting to cover multiple legal avenues with a common sense filter. That's fine...