I implemented this pretty easily just using events. Instead of adding a friend I instead send a 'friendRequest' event to the potential friend. once that player views the event and accepts the request the friends are added.

Hi Ali, First of all - sorry for the slow response. I somehow missed this message. The MultiSocialLeaderboard call is normally used to create Candy Crush-style maps - where you would normally show just the top player on each node of a map. It's otherwise a pretty expensive call (as we're filtering/joining your friends list with multiple leaderboard lists) - so thus we restrict things to keep things fast and server utilization reasonable. Do you have a use case that requires the larger leaderboard sizes - or maybe you were mistaking the intention of this call with another? Anyway, hope that perspective helps! Cheers, Paul.