So, Fusion almost had a sequence break. If you have an event value that is higher than the event for the Omega Metroid dying, you can enter the destroyed docking bay. From here, you can trigger the Omega Metroid to spawn, but it'll just keep swiping you and you'll become softlocked. However, if you exit the room (before triggering the fight) and reenter it, you'll hear the Omega Metroid dying (even though it's not there) and the ship will arrive, allowing you to beat the game.
With the out of bounds memory corruption (as seen in my latest videos), you can set some values to 0, but there are also a few you can set to 0x80. The event for Omega dying is 0x6C. So theoretically, if you can corrupt your saved event value to 0x80, you can beat the game early.
The corruption works on 2-byte values, so the value we'd want to corrupt is a combination of the event value and the number of abilities obtained (ranges from 0 to 16 or so). More specifically, the value would look like 0xYYZZ, where YY is the event value and ZZ is the number of abilities. Unfortunately, only a small fraction of the possible 2-byte numbers get changed to values greater than 0x8000. In this case, none of the possible event/ability combinations worked.
You can see the list of values and how they change here:
http://pastebin.com/YK8jXFb9
Pretty lame that it just came down to luck. Fusion just doesn't want to be broken.