By jumping from the first halfpipe into the corner of the billboard wall, you can clip right through the wall and freely skate outside the course. From here, you can do several other tricks outlined below.

If you bring the Death Ball out of bounds during a race, the CPU's AI will stop working and they'll just stand there until it returns. If you throw the ball out of bounds, the ball disappears and they'll be stuck forever.

Against Immortals and Love Shockers, it's actually faster to kill them than to do the normal race. The optimal strat now for Death Ball is to grab the ball, do Exterior OoB, wait for them to get close enough, then throw the ball away from the course to freeze them, making them easier to kill.

When you throw the ball away, be careful that it doesn't rebound off of some collision and go back inbounds, or else the AI will unfreeze and continue the race.

Physical combat in this game is extremely wonky, so when you're tackling them, sometimes they just don't take damage, and sometimes you'll even be knocked back. The most consistent strat is to tap them from behind at a slow speed.

This strat is not viable against Doom Riders as they have too much health.

After talking to the Noise Tank at the beginning of the chapter, you can mash Start and A to repeatedly pause, which delays when you get teleported. You can use this to reach the load zone behind you, but it rejects you, making this trick useless.

You can pickle through the gate near the beginning of the level by skating through the right side. It seems to help to center your camera to the right of your character, and skate to the right. Once you're in, there's no way out, so this should only be done during Jazz's tutorial, or else you'll softlock.

If you try to exit the level while out of bounds (after doing Exterior OoB), you will become softlocked and must be teleported out by the end of the Jazz tutorial. This is because the load zone tried to reject you, but is unable to do so since you're blocked by the wall.

If you do Exterior OoB and then try to leave the Expo Stadium during a match, the game will warp you the center of the map. No clue why this works, most likely the load zone was not programmed to take you anywhere (or reject you) and so just puts you at a default location.