I see now, not to be mean but that's the dumbest thing I've ever seen. The setting for the default board style, either by board prefs or by setting the style to default in style management, should be the setting for the "default" (by default I mean the style that is seen by guests) board s...
I've been having the same problem, I've tried to change the default style many times on 2 different forums (both using 3.0.2) and it never changes, I've even tried changing the setting in the database and it still doesn't work.
I thought this mod wasn't going to work with the Gold release until I remembered something, you need to refresh your template cache in order to see the button/form...