Quoth the documentation:
- add custom menu items that do not map to existing FileMaker Go menu items
This makes the feature utterly useless for those deploying complex mobile solutions. We must instead produce our menu interface and replicate said object across countless layouts, and keep them up to date. Why can't FM go simply display a nice clean text menu across the top of the window with the defined custom menu's contents? Most developers would not care if the menus look iOSy or not if they could have a single central means of controlling access to various actions. Automatically translate the menu into a new top-level layout part if you must, it would be worth it to have this feature.