Error on my side, I was talking about the Share leaderboard update event that I can't get to work.
Anyway, I just did a couple of tests, and you're right! It's very easy to use Share/Invite event. That's finally what I wanted — Players to send their score directly to a friend via a message, or create a new Facebook post about.
Share leaderboard update requires that you play the game within a context, and the leaderboard has to be a contextual one. If that is the case, you can set an update ledarboard event, which will automatically send an update message with the score to the context you are in. it will be seen in the context later, but you will never notice anything in the game itself.
This feature also works fine, I have tried.