The macOS application menu (with about, quit, ...) is not translated. (The mm3d menus are translated.) Qt translates the mac app menu if a global menu bar is used but not if per-window menu bar is used (this seems to be a Qt bug). The mac app menu is initially created before it's possible to add translations and the translation is updated when, if I understand correctly, a window's menu is attached to global menu.
Maverick uses per-window menu bar because I haven't managed to make the global menu bar have a separate menu for when all windows are minimized/closed. It might be worth looking into this again with Qt 5.15 which would also fix this translation issue.
The macOS application menu (with about, quit, ...) is not translated. (The mm3d menus are translated.) Qt translates the mac app menu if a global menu bar is used but not if per-window menu bar is used (this seems to be a Qt bug). The mac app menu is initially created before it's possible to add translations and the translation is updated when, if I understand correctly, a window's menu is attached to global menu.
Maverick uses per-window menu bar because I haven't managed to make the global menu bar have a separate menu for when all windows are minimized/closed. It might be worth looking into this again with Qt 5.15 which would also fix this translation issue.