There is a huge hole in Glitter Gulch Mine that you can glitch through if you have a high enough speed. With the Super Banjo cheat enabled and the power of wing wack or crouch sliding, you can have just enough speed to clip through and glide through the level. You could probably access a lot of the locked areas with this such as Waterfall Cavern, Canary Cave, and Flooded Caves. Also a cool glitch to show off the level in an out of bounds view. I'm also thinking there could be some more applications of Super Kazooie in clipping through small gaps.