True, we do only know Radical Dreamers through Demiforce's translation, mostly. I guess by "polished" I meant complete. The story feels complete to me, even if the ending is a bit open-ended. But I can live with a few unanswered questions.
Original point being, if Kato had enough time to write half a dozen extra scenarios, I can't imagine what else he had in mind for it. It's interesting to think about.