Go to a gay cruise. The homos are well-behaved at the buffet queue. They like to party late so you won't get the usual morning breakfast crowd congestion.
Buffet is never the right cuisine for Tiongs, to them must always Ala Carte menu, order their food & charge individually
Food wastage is in their DNA ... forget about using penalty on leftover food, they will argue until the sun goes down !
Very simple solution: just ban all Tiong customers. Trust me, you will end up making a net loss by letting them on board your cruise ship. Don't forget they steal and damage property too. Just create more negative PR for your company. Not worth it.