Had this trick with a friend a few years ago. Level 10 is the only boss stage where you can jump off and die, meaning you can get faster times. My PB (WR on Cyberscore) is 11.83s with this trick.

Just got back into it, so wicked rusty (and the fact that all my best times are on my 2DS).

https://imgur.com/a/SnhZ6eB