No, you must complete Paper Mode Ending in order for the glitch to work. Game Overs and resetting the game in any way will nullify the glitch
To my understanding, the glitch works as long as you don't die or reset, but if that happens, you won't have the glitch anymore. That's just my understanding. So technically, I think you'd have to complete the pit in one sitting.
Ok, to clarify, the glitch only works if you go through the credits because Mario's state is not reset from being stuck in Paper Mode. If you game over or reset the console in anyway, Mario's state is reset.
If you are wanting to setup for the Pit before Chapter 1, just setup a file where you have every badge/item that you will need for the pit and save at the save block in front of the Thousand-Year Door. Reset your console and pull up a save before the Shadow Queen fight. Perform the paper mode glitch before (with Bobbery glitch on the door to the Shadow Queen's chamber) or right as the first phase ends by holding R and a direction before the cutscene begins. Beat the Shadow Queen (you can let go of R at this point) and watch the credits all the way through. Do not reset the console at any point and boot up the file that you had setup for the pit and press and hold R as the file starts up. Continue holding R until you are able to pass through the bars and use the plane panel to get to the Pit door.
If you die in the pit, you have to perform the glitch all over again. Keep in mind, the process of resetting the glitch is very time consuming
Hopefully this explains everything you need to know.
