Friends List and Invisibility

While I know League is a team game and Riot wants everyone to play with friends, I am sure that everyone at some point has wished they could just appear offline to play solo, or maybe get a game or two in before joining you friend who is prone to raging very audibly.

I would love to see an invisibility system of any sort implemented. As of right now if you're online, people know if you're recently active, if you're in a game, how long you've been in it, and everything. Sometimes you wanna go off the grid and play without telling your friend "hey, I need a couple games to myself. Please understand."

So, opinions welcome. Or if there's information or sources as to why this doesn't exist already I'd love to hear. I'm always surprised a more versatile status display hasn't been put in