If anyone is reading this, Seoul Hyatt feels sucky. They play lots of games, just be aware of that.
1. They also do minimum nights, if you search for a single night for example GH Incheon, it will show no availability, but somehow when expanded to 3 nights, the base room magically appears. You can book it then call Hyatt to modify the dates manually.
2. They change the base room ever so slightly to block point stays, for example base room + high floor = invalid for point stay.
Haven't started my stay yet but already feels like Seoul Hyatt tries to minimize WOH program and just want to maximize being just random hotels.