should H4 to H1 COS get visa stamping to start working?


My spouse was in H1B and got laid off . His I-94 is valid until 2020. He hasn’t travelled while on H1B visa so he has no H1 stamping. He was in F1 and transferred to H1B upon his job. So F1 is the only stamping he has in his passport. When he lost his job we applied for his H4. H4 is not approved yet. Meanwhile he got a job and that employer filed for H1B. but currently they are trying to clear his RFE. My question is, what happens when H4 gets approved first and then his H1B. Please note this employer didn’t file for COS H4 to H1 because they filed for H1 by 60 days grace period of he losing his job. In this situation does he have to travel to India to get H1B stamped before he can continue to work? Another question is, lets say another employer is filing for his H1B while the current employer’s H1 is pending and the H4 is approved. So they will have to file for H4 to H1 COS. In this case, does he have to have his visa stamped before working for this new employer since it was COS from H4 to H1?