There is a reason for why they (Governments) let banks in Puerto Rico live and allow the activity they are doing. On a short term I believe they let them do what they do because they are investigating and use these banks as honeypots.
On a long term, maybe it benefits the US or other governments to have most of these operations in one place, it's easier to turn the switch off if it's required.
That's basically it. They are watching i.e the Venezuelan transactions flowing through some of these banks. The Feds can watch certain operations around organized crime for many years before making their move. There is zero chance the mass surveillance tools of the US government is not aware of what is happening in the Puerto Rico banking︀ scene.
Puerto Rico is also broke and are happy to turn a blind eye to some or most of what goes on with their international banks, as long as they can rake in some license fees and what little tax revenue they earn.
I think after EPB's recent scandal maybe not. Best to ask EPB directly unless there are people here who recently opened a SC company account with EPB - and I mean opened in last few weeks.
I think the problem is your suggestion was for a solution from 5 years ago. In offshore banking years that like 150 years ago 😕. The world is a different place now for banking.