Hmm, maybe I will make the tiles needed.
It seems fairly simple. The backdrop won't be 'normally' possible, though pulled off if a scripter knows that they're doing.
Also, Death Mountain wasn't that complicated, at least in its structure. The only 'maze'-like feature was the cave system. I also doubt the mountain's were random at all, you can't make a high-caliber game like Zelda and not have level design carefully planned out.