Has anyone tested to see if KoC can do GMS original stuff?

That's what I don't get. Aran is a race but Cygnus is not? o_0 It's not like Cygnus = Adventurers getting new classes, imo. It's weird how they have it in the data then, because it's not like:

Beginner -> Archer -> Hunter/Crossbowman/Windbreaker

It's:

Noblesse -> Windbreaker -> Windbreaker (again) -> Windbreaker (and again)

No windbreaker in the data

Noblesse => Intro of the Wind Archer => Skill of the Wind Archer => Path of the Wind Archer (=> Completion of the Wind Archer)

Their beginning class is just different.

I don't know how Aran races are implemented, but I suspect they're implemented the same way.