A glitch has been discovered to go oob to skip most of world 1, all of world 2, most of world 3, and all of world 4. Is this allowed in Any%?

Idk

you cant skip world 4

I heard you can skip past world 4 or 5 but you can't unlock the final Bowser stage without them, not sure if that's true

multiplayer isn't allowed soooo doubt

You need the Royal seeds from Worlds 4-5-6 in order to unlock Bowser's Castle. The only Worlds you can skip are 1-2-3.

multiplayer isn't allowed soooo doubt

As of today, multiplayer may be used in Any% as we created a new category for runs doing the skips with the use of multiplayer, however it's banned in All Royal Seeds and hundo.

Also yeah, you are required to beat w4, 5 and 6 to unlock the Bowser stages and beat the game. So skipping w4 would be just useless.