the plugin, combined with BuddyPress will generate notice. for more information see : https://buddypress.trac.wordpress.org/ticket/4830
"Some plugin is invoking it (set_current_user) too early. You'll want to do a debug_backtrace() and figure out what function is calling it when."
seems to me you have to use is_super_admin() on init, and not before on class construction.
very helpful plugin btw, thanks