I'm wondering why emulation is allowed for Radiant Dawn, but not this game.

Emulators aren't allowed for both this game and Radiant Dawn, and the rules don't say they're allowed.

Radiant Dawn has the checkbox "Emulator" on the submission page enabled. On the POR page, it says "Emulators are banned". If both games have them banned, maybe that information should be included on the RD submission page as well.