Obsidian is Pretty AnnoyingListen man, I'm fully aware that nobody actually uses these forums anymore. Except me. But I'm here to tell you that it was a bad idea to make 15% of Z-Mine obsidian. It prevents any kind of fly-mining, or even jumping. Literally any other block in place would be better. Diamond block, coal block, emerald ore, you name it. The mine wasn't even designed to contain obsidian, the builders didn't have that choice. It just kinda stinks compared to the last mine which had diamond, if I'm correct. I don't think it would be that hard just to change the item type, because a lot of people use that mine and a lot dislike it.
That's just my opinion.
P.S: I am fully aware of how unnecessarily dramatic this post is. I don't regret it.