Go home now bringing AP.
In recent memos, O1 is consistently excluded as the visa type that can reenter after filing I-485. So, once you leave US, you must use AP to return and you loses O1. and after reentry, he has to work using EAD.
If he still has H1 time left, and if his I-140 (EB1b) got RFE in the future, he should ask school to sponsor H1 and get the I797B. If I-140 really gets denial, you two can still go out to get H1 and H4 visa stamp to return to continue.
In recent memos, O1 is consistently excluded as the visa type that can reenter after filing I-485. So, once you leave US, you must use AP to return and you loses O1. and after reentry, he has to work using EAD.
If he still has H1 time left, and if his I-140 (EB1b) got RFE in the future, he should ask school to sponsor H1 and get the I797B. If I-140 really gets denial, you two can still go out to get H1 and H4 visa stamp to return to continue.