The major issue with the Jones act is that it prevents domestic transport of goods on water unless it is a built/flagged US ship. This accounts for a tiny fraction of transport within the US (3%):

https://data.bts.gov/stories/s/Moving-Goods-in-the-United-St...

Getting rid of this single part of the Jones Act would help a lot, and I don't see it hurting, as it accounts for such a tiny fraction of our transport today.