Ah, that uses a property of secret level exits I was unware of. I didn't realize you could have more than one, and have JJ2 remember you visiting each one. Of course, that behaviour was implicit in the JJ2+ readme, but I guess it never got through my head. I am also surprised to learn that triggers are preserved in the hub level, even if you go off and visit other levels.

That's neat. It's a really nice example of what can be done, and a system using the sort of hub you've demonstrated will completely avoid the 200+ level problem I described above. It's more flexible than the solutions I had in mind, too, and functions very smoothly (it doesn't feel like a weird hack). I'm quite impressed. This is one of the coolest things I've seen done with JJ2 in a while. I highly recommend you create a tutorial of some sort, for other people. I can understand how it works by looking in JCS, but there could be a lot to gain from some sort of jcsref article.

(just so you know, I wasn't thinking of secret level exits at all when I wrote my long post. I was assuming regular level exits would have to be used)