*** Edited *** : Don't use this, use Update 126.96.36.199 instead.
Now it should be possible to use BungeeJail with MultiLobby.
If a jailed Player connect to the Server and "allow-hubconnect" in the configuration is true, then the Player connects to a Lobby with the lowest Player count.
I do not have tested this Update but im sure that it would do great.
If you found any error please show it to me so i can fix it.