i don't really understand how you would get full credit. if you mean roulette's, then simply force disable that option for roulette's. otherwise, i don't see any other way to get full credit.

in any case, the option is just that... optional. i don't see how it could cause any harm. and it would make it easier to get someone from your FC or LS in to your in-progress. i can't count how many times i've asked for help from a tank or healer, but for them to not be able to get in. of course, it would be much nicer to just simply be able to invite an outside player to your in-progress instance.