What restrictions on priority date retention?

  • I received my H1b (not H1b1) visa stamp in early 2017. My Singapore passport expires in Sep 2019, and my H1b visa stamp expires at the same time. * Apr 2017 I first used this particular visa stamp to enter U.S. Now I’m in the early stages of GC. I hope to get my pending PERM approved in early 2018, under my current employer P. Once I get my priority date, I plan to relocate back to Singapore for 2 to 3 years, where I will get a new passport. I will need a new visa stamp – is it hard? I assume it’s not hard in Singapore. * When I re-enter U.S. to work, perhaps 2021, on the new H1b visa stamp, I will probably work for the same employer P, or possibly a different employer. Will I keep my priority date? Friends tell me to beware of risks and complications. Are there?