Well, hold your horses, there are still federal taxes, including capital gains tax. It's not written very clearly.
The only no cap gains tax for US citizens is the Puerto-Rico deal, but it is only until 2035 and only on cap gains AFTER you domesticated/moved your assets there.
Plus, you HAVE to reside there 183 days/year.
Yes but federal taxes dont apply to offshore assets owned by foreigners. This is about tax rorts for foreigners, not Yanks