This has the ability to save 10-20 minutes from the current route.
There are a number of things that makes it faster.
1 You only grab the equipment you need in Onett. You do nothing else in Onett. You Skip the rest of it.
#2 When you go get Poo, those levels still go to Poo even though you're Ness. This will help big time.
3 Once you get to the Fight with Giygas, Poo can use PSI Starstorm Omega, maybe even twice.
The one problem being that I have no idea how to figure out RNG Manipulation. I do know however what needs to happen. Reset after save in video to reset RNG.
You need to go though almost all of the Magicant path without fighting anything. I say almost because now that you have 4 Characters, you need more Exp. to get the right PSI.
RNG Manipulate the game to where you fight those DNA??? Monsters that don't attack you at the end of the path where the stick is. I don't know how many you need to fight. I'm guess around 8 or 12. So 2 fight of 4 or 3 fights of 4.
After that do what the old route was already doing.
Give Jeff Horn of Life before Giygas fight if Poo can use Starstorm Omega Twice.
The Giygas fight will be different depending on how many times Poo can use PSI Starstorm. If only once, use it on Porky. If twice, use one on Porky, Poo will probable die do the Giygas' Reflection. Use Jeff to revive Poo. Then wait until the 2nd phase starts(Where you see Giygas' face for the first time) and use PSI Starstorm a 2nd time.
Rest is history. Good luck with RNG Manipulation.