It's a bit of a further tangent, but my understanding is that this has a particular weird impact on cruise ship destinations and related tourism cash/investments. Because cruise ships aren't exempt from the Jones Act either and are often foreign flagged (many cruise ship companies are nominally headquartered in the Bahamas and fly Bahamanian flags on their ships), they also have to make sure that they alternate ports in the way that meets the Jones Act. They can't go from Florida or New Orleans straight to Puerto Rico without stopping somewhere else first (and with US sanctions still "weird" with Cuba the obvious stop isn't generally possible either) or travel directly between Puerto Rico and the USVI without a stop somewhere in between (such as DR).
This seems silly for a number of reasons. I know a bit too much about it because a cruise charter group I go on cruises with has wished for certain itineraries to make logistics easier (PR has better concert logistics than most other islands, for instance, if you are trying to set up a single day concert in a park), but there are too few available PR routes for the sake of variety precisely because some of those routes that might be desirable are basically illegal under the Jones Act. It's not a showstopper in this group's case, but it is silly.
This seems silly for a number of reasons. I know a bit too much about it because a cruise charter group I go on cruises with has wished for certain itineraries to make logistics easier (PR has better concert logistics than most other islands, for instance, if you are trying to set up a single day concert in a park), but there are too few available PR routes for the sake of variety precisely because some of those routes that might be desirable are basically illegal under the Jones Act. It's not a showstopper in this group's case, but it is silly.