Hello. mountai is a server run (mostly in absentia) by a friend of mine. It occasionally goes down and is brought back up as quickly as one of us can reach out to him. This does mess up the chanserv info sometimes. It's certainly not an ideal solution, because it definitely could go down for good someday. However, the question about problems after a certain number of users joining is just user error or client-side trouble. mountai used to host 80-100 connections at once regularly without any issues. [EDIT: maybe more, shit, I had forgotten all about that minecraft group. Now I can't even remember how we know them.] Now it sits at about half that, I think. There is next to no way the problems people have experienced are, bluntly, not their own fault. (Don't use mibbit!) Nothing wrong with switching to freenode though, it's what everyone else uses.
Yeah, I've never had an issue with my client, though others have reported some. I also suspect it's a mibbit issue. Another option is if your friend can reset the channel and give someone operator status, then we can register it with ChanServ and regain control. I'd personally still prefer moving to freenode, unless your friend is planning to manage mountai for years to come.