I seem to recall the BVI passed a law some years ago requiring any restaurant that imposed a service charge to set up a committee, including at least one back of house person, to determine how the money would be distributed.

They all hope tourists will miss the service charge and leave another 20% - at least I've never heard one say "Oh no, you've already paid a tip!"

In my mind, if your kitchen help should earn more, then raise their wages! Of course that would cost more, even during slow periods. The service charge is a way of paying them more when the restaurant is busier.