Here are all out of Bounds clips I found:
1-3 Get into the watering can, walk up and spam jump. You should then clip out of bounds. If you then go back to the beginning of the level, walk below the first grass blades, and jump, moving down and back up to scale the grass indefinitely. After a while, you can jump back in bounds or onto the wall and explore a bit.
2-1 Stand on the rising rock in front of the acorn and let it rise to the maximum. Then jump perfectly to the highest platform, where you will only stand on a small piece of ground. Jump perfectly up again and you will be able to get out of bounds. There you can explore and with another really good jump get onto the red bounding walls of the sandpit.
3-2 You need to be in the area after the checkpoint and walk to the key up ahead. But you don't go to the right but to the left after collecting the key. You will then again stand on a small sliver of ground and jump around moving in small intervals up and down until you stand in the air. Then just repeat everything that I described in the 1-3 infinite height glitch but move right and left instead of down and up while jumping. You will come across a floating cage if you do this right. When you feel you are high enough jump somewhere, where you want to go. If there isn't an infinite wall you will get out of bounds or maybe in the cage, I haven't tried that yet.
4-3 I stole this clip from -GameDevIsTaken-:
Sadly I haven't found one for World 5 :(
Anyway, thank you for reading this TEXT WALL OF DEATH.