Could there possibly be an event where Jeeb spawns in the realm, make it very difficult and when it dies it has a slight chance of dropping jeebs keys in a white bag or just drop a Jeebs' Arena. Obviously make it spawn at a low rate so there aren't Jeebs every realm or every 10 minutes. Just a suggestion.
I think the current rate of incomming jeebs arena keys is good enough.
I like my jeebs rare.
Ya jeebs are very op the current rate at which people open them is fine.