First off, you can't register any sooner than five days before your flight arrival at St. Thomas. No jump starting there.

Second, turn around time is related to when you will arrive. Best to wait until the day before or day of your arrival date - the closer dates receive precedence. Response time is pretty quick when you do it then.

Third, yes, you only need to be fully vaccinated (or have negative test) to complete USVI travel portal, however, if you will be continuing on to BVI, you will need to have negative test results, either proctored rapid antigen (like BinaxNow) or PCR.

As of now you will also need to test negative to return from BVI to USVI. Same types of tests. Hope this helps.