I agree that it's not a HUGE advantage however it does mean that you can switch faster. Think about where your hands are while playing. To switch normal you have to move to the middle of the screen, with this you just move your hand very slightly down. Not a huge advantage but still.
Also no, if the watcher bans you for it you can't just say 'oh so and so said it was ok'. For two reasons.
1. This makes lying a lot easier for anyone who uses hacks
2. if the watcher bans you, whatever you were doing is definitely not allowed