Stefan,
Gorm cannot edit menus in any other mode but the NeXT interface style currently. Gorm overrides this setting to prevent issues during editing. The eventual solution to this is to make Gorm display the menu in the desired style so, but that is still pending.
I understand that's the only way that menu editing can work with Gorm, but I'm not talking about the editable menu, I'm talking about Gorm's Main Menu. In previous versions of Gorm, whenever I had the default set to Macintosh menus it would display the Gorm menu horizontally and the developing application's menu vertically, which is in my opinion better than just overriding the user's default settings.
Stefan