I think the BVI (and all organizations using PCR testing) need to disclose the Cycle Threshold (Ct) where they consider a test to be positive. If you run enough cycles (for example, 40 or more) a very large number of people will have "positive results" due to genetic fragments from some prior infection (COVID or possibly something else). A Ct of somewhere around 30 is much more likely to accurately indicate a "real" case with fewer false positives. A false positive, for an arriving tourist, could trigger a series of events that would result in an unpleasant experience. I realize there may be some false positives - no test is 100% accurate - but they really need to tune their reading of the tests.

In order to make sure that a test performed prior to departure is "valid" for the BVI, both tests (before travel and upon arrival) need to be interpreted with the same Ct value. Else it's the old apples to oranges problem.