I suspect perhaps the broker was looking at a timeline for the entire process. Depending on where you plan to spend the night it could knock half a day off. He may also have been including transit time from the USVI. Usually I try and combine customs with a stop or lunch I would do anyway. The new rule is going to be interesting. I normally have someone hover the boat while I jump in the dinghy and clear in or out. Now you're going to have to find a ball or anchor since no one can remain on the boat. That may not be easy at Westend or Jost depending on the time of day. Last time clearing in at WestEnd we wanted a ball to go have lunch. Nothing came available so we left for lunch at WB. We would have been waiting a long time if everyone had to go into customs.
If the BVI is serious about the rule they should install some customs use only balls in great harbor and Westend.
G