As someone who worked offshore on a contract in Asia (but not in China) as I understand it to satisfy the PRIA the airline need only attempt to contact a foreign carrier for the records. Still, it would be wise to keep photo-copies of your PC's, resignation letter, etc.
Although, you can cross FedEx off your list, (and maybe UPS, + perhaps others) for 5 years after you return because they will not hire pilots who've flown overseas (excluding military and, get this, missionary work). Reason: They have a major USPS contract, and since you've worked overseas obviously you're a terrorist. This is the USPS's doing and not any one carrier. This is troubling since, besides being a stupid contract stipulation with no basis for support, when I was furloughed in the USA I was flying the same freight/company owned aircraft before I left for overseas. USA=dysfunction. Good luck.