Option to show Menu Bar icon only when specific displays are connected

[Empty2k12]

Allow for more granular options when the menu bar icon is shown.

Current behavior

The menu bar icon display can be toggled to either on or off.

Expected Behavior

I would like to hide the menu bar icon when I am using only the internal display. I am thinking to disable the menu bar icon and in the specific display settings a toggle to override showing the menu bar icon. This way, I could individually select when the menu bar icon is shown based on the connected monitors. However, this approach would also hide the menu bar icon when a new monitor is connected, as the showing is now opt-in per monitor.

Next steps

It would be good to know if this feature would also be of use to other people. Additionally, it should be discussed what the best options are, should hiding or showing be opt-in / opt-out or both?