Fixed the thing you are talking about by adding stages early that forces the use of the purple hair mechanic.
And some visual tutorial
I am not sure if the bug you are talking about is regarding the height and sometimes the dash would go diagonally when it shouldn't but I fixed that, all superdash when on air should go as far as the one on the ground and should go straight in your chosen direction.
I really didn't know about Coyote Time previously and you mentioning it really helped me polish this game, thanks. I have implemented it on the game.