Well if there are still participants who haven't sent their payment details yet, it's because they are not aware that they ought to do that.
Maybe you should send them personal messages as a gentle reminder.
It is every participant duty to keep checking the signature thread they are or were a part of until they get paid.
Lots of other people suffer due to their negligence.I am facing the same situation in zdash campaign.Just because not all participants sent their address to campaign manager,all payment is withhold