I have current H1B status until Sept 2012. I also applied for a green card (concurrent I140/I485) under EB2-NIW (receipt date aug 3), and my I-140 was approved (on August 14th), as well as my EAD and AP, and I-485 is pending (was fingerprinted on Sept 9th). I have to travel abroad rather urgently, and I would like to use the AP to spare myself of the trouble and cost of applying for an H1 visa stamp (I never got an actual H1 stamp since I've been on H1 status to not risk security clearance delays).

My question is, if I re-enter using AP (but resume work with the H1 employer), if my I485 is god forbid denied despite the I-140 approval, can I regain my H1B status w/out leaving US? What is the procedure for that? Would it be advisable to apply to regain H1B status as soon as I re-enter?