no only SERVER SIDED.
only staff and beta users can cheat on the CLIENT for now until the release.
how to get beta access u need to use the software at least for 5 months after that all ok.
if you dont want to than wait for LC3.0 which might take 2 months to release and after that you will be able to buy it after 2 months of sub only not 5.
hope that answers the questions.
multi league can be used on all leagues that are server-sided.