Find yourself a 'qualified, trustworthy' tax advisor. Act 20/22 (and a couple others) has pretty much passed it's time. It's like a boat starting to take on water and you're hoping to just go to a higher deck and ride it out for as long as you...
If all you're looking at is getting away from US Taxation.. there are better ways.. better places for that..
If you intend on moving to PR for life anyway, then yes, take full advantage for as long as you can. That only makes sense. Be prepared for a lot of paperwork to make it work.
Good luck on your quest