It may be so, but if you are paying withholding to PR, and not federal tax that sounds like a dual taxation convention coming into play. Are you also saying the IRS waives CGT if you are non-resident? I’d think, either you don’t report everything to the IRS (you get about an $80k exemption anyway), or you have to give up your citizenship, if you want to avoid/evade taxes. If you do that of course you’ll get hammered with an exit tax. They’ve pretty much got you by the short and curlies.
