After seeing the water bottles I attached a cel phone to my P4 last weekend and delivered it to my neighbor. I had no idea it could deliver something.
Now I can deliver beer from my deck to guests outside.
I assume that the motor with the modified prop is probably spinning a bit faster to compensate for the loss of the tip of the propeller. It is interesting to carry things but swinging/dangling things create a pendulum effect with can alter the way the drone flies and responds to inputs.