Everyone developing a FileMaker solution for macOS should get the MBS FileMaker Plugin and configure the toolbar contextual menu with our Window.ConfigureToolbarMenu function:
As you see, you can configure the toolbar menu to remove the whole menu (mode 1) or hide only the entries to show/hide/configure.
For mode 1 we skipped the screenshot as simply no menu shows up.
If the user is allowed to configure the menu bar, he can enable commands you may have disabled via custom menus and work around your security concept. Like if you disable delete, import, export or print buttons and the user configures the toolbar to restore it.