RFE: click on the menu icon starts a default Item

It should be possible to define one menu item (or simply start the 1st item in the menu?), startung by default. I can propose two behaviours:

1) default item will be started on double click on the menu icon

2) menu is opening on mouse down on the menu icon.
default menu item is starting on mouse up on the menu icon.
dragging mouse outside the menu icon closes the menu.