As an H1B visa holder, your spouse-to-be may travel in and out of the US freely, even without AP while his AOS is pending. What matters is that he keeps to the terms of his H1B visa, like staying at his job at the company that sponsored him. I recommend that he NOT use his EAD/AP after they are issued, so he remains in H1B status. Filing for EAD would have no impact on his H1B, as long as he does not use the EAD (ie, does not notify his company HR that he is switching to EAD holder status). Still a good idea to file I-765 and I-131 anyway as backup, in case he ever decides to quit his current job while his I-485 is pending.