Low% would probably be fun, as it is for most games.

This happened randomly when I was messing around, idk if that's how you'd recreate it or not. Somebody can test it in TAS

You can clip through the cannon at the top of death mountain, idk if this is useful information for 100% or not. I don't have video footage, but if you hit the top edges of the cannon right (before it's rebuilt), you can clip through and go OoB.