In our legacy COM-based add-in add-in, the buttons defined programmatically in our ribbon can have a "default" action that, being clicked in the "main" button area, does not open the drop-down menu but simply triggers the default action defined for that menu:
However, in the Office.js API, the dropdown always opens without an ability to define the default action.
1. This results in extra clicks when the default action makes sense in 95% of the cases.
2. This results in a UI discrepancy between our legacy COM add-in and the new add-in, which makes support more difficult.
