I know there is a way to cheat. Has anybody tried uploading Danish articles? Please share some links with me. (I'll give you lingots)
I wouldn't call it cheating. In my mind it's just an unofficial (and perhaps incidental?) backdoor into functionality that exists but isn't "production quality". For example, the Danish word list is barely usable (more than half the words are obscured by some internal DuoLingo placeholder) but the flashcard feature you can access on the same page actually functions without any limitations. YMMV.