I have tried to give out my ideas for testing, but no one ever shows any interest.
Well, generally, you have to give us an idea of what it is you're doing before we can show interest.
I still need to test it but here's my plan: I was thinking the other day that there has to be some way of distorting/corrupting the cutscene where you draw the MS, which made me think of OoT. The only recapturable bottle item in WW is the forest firefly, so I was thinking of doing corruption similar to OoT.
Hopefully, here's where I'll probably lose you, by corrupting the scene you'll be able to draw the MS, but not activate the cutscene so it's still in the pedestal. Drawing it multiple times with this could--hopefully-- result in EPMS; game overiting. This is the most likely of my many EPMS+GT early theories.
Yeah, corruption isn't really the right word, it's more of displacing Link during the scenes to potentially mess them up.
I'm not sure that will work, because the moment the scene starts, it changes the flag that removes the Master Sword from the pedestal. I know this because when you try to use Storage on the scene, the scene will start anyways, and Link will get crushed (for some reason), and the Master Sword is gone. You don't even get it, so you're trapped forever.
Another thing though, I don't think getting it multiple times will "upgrade" it, as the Hero's Sword, 0/2 Master Sword, 1/2 Master Sword, and 2/2 Master Sword are all different items. The scenes that give them to you do just that, give you that item. It isn't the same item being upgraded. So, if we can somehow fight Molgera with say, the 0/2 Master Sword, we'll get 2/2 Master Sword rather than the 1/2 Master Sword. The game was programmed in a way that you couldn't get the power ups out of order.
However, I like the idea of using the Forest Firefly similar to the Fish to mess up scenes like in OoT. Unfortunately, what I'm thinking, is that the bottle swinging has higher priority over the scene, and it'll put the scene trigger off until after the animation ends.
You should still definitely test it.