Even though BVI mimics US "screening and quarantine" policy, the BVI does not have ability to house and quarantine even a few dozen people. So the ferry being unloaded is not going to be directed to a Quarantine Building. If overtly sick(fever), you may be denied admission (and sent back on next ferry?). Quarantine could be potentially, go directly to your villa/charter boat and do not go to shops/bars/restaurants, etc
Or am I wrong about the BVI Quarantine capabilities?