Tip: If you give a Muncher tile custom graphics, it will still act like a coin when a silver P-switch is active, whether it looks like a coin or not. So make sure to use ExAnimation if there's a silver P-switch in the area.
Does this glitch works on platforms too if you stand on two of them at the same time? This happens easier with line guided platforms.
I think how this happens is that both platform will try to displace the player to move with the platform, the problem with that is if they are going in the same direction, the displacement will combine and pushes the player abnormally.