Actually PR and USVI use the IRS tax code, and for USVI add +10%. There are some local tax breaks in both place for international, non continental us business activity. PR does have some kind of tax break on 'investments' but I don't know if that is only for passive investments, as opposed to your own business. But this is a good suggestion as it is in the USA and is often a great tax deal, with the catch you have to spend less than 180 days per year in the actual states, and spend at least 6 weeks per year in those two US territories. I think you have to spend New Year's Eve there too!
Residents and businesses here file taxes with PR's Hacienda, not the IRS, therefore Section 174 doesn’t affect PR as far as I know. On top of that, PR already has several tax breaks and incentives that may tip the scales even more for some.
It will be a very interesting year though as the head of Hacienda just resigned, so it’s anyone’s guess as to how we’ll end up.