+5 Yes, Puerto Rico is widely considered a colony—or often described as the world’s oldest colony—due to its status as an unincorporated U.S. territory. While residents are U.S. citizens, they lack voting representation in Congress, cannot vote for president,

From the first article you linked:
Don’t get me wrong, I hate the Jones Act as much as any rational American would, but from what I hear, they get a grab bag of exemptions on taxes when moving goods to/from South America (I suppose via non-US ships and via aircraft).
I don’t have the time for proper research at the moment to try to find what my dudes have talked about when it comes to laxer import/export controls, but may revisit later today if I get some down time.