Converting Add-in to Extension package

Hello,

I have an Add-in that runs in VisStudio 2012 and VisStudio 2013.
It does not have any UI; it monitors and responds to focus events.

When I converted the add-in to an Extension package (starting with the template provided by the VS2013 SDK), it works as expected when I have a menu item.
However, until the menu command is used, the package doesn't seem to get fully initialized.

How can I force the full initialization of the extension package when it has no UI?

Thanks for any insights --