Is Firefly a constructible gate, or is it special?
Firefly has The Jelly Farm on one floor, and The Jelly Farm II on a different floor. Each floor has levels from different Aurora Isles.
Every gate I've seen built in the arcade would have both on the same floor. I haven't seen a floor break/mix sets like this.
Is it safe to draw conclusions from Firefly, or should it be ignored and regarded as an "exception to the rules"?
Yes it's premade. That wasn't the question.
The question is: Can a duplicate of it be built in the arcade? Or is the construction for it "special" and not replicatable?
(It is ruining my construction hypothesis.)

There are a couple of level in Firefly that will not spawn in the arcade gates. They're generally the easiest of our static levels so it's of little loss to players who never run Firefly.
So that would be hall of goo and hall of the wild, right?
What about Jelly farms 1 on one floor, and jelly farms 2 on a different floor? All the gates I've seen built in the arcade put them on the same floor.
Of course it's premade.