I currently have a H-1B visa which is due to expire in March 2022. My H-1B extension was submitted in June and is currently under review. I will soon be going on work-related travel for a number of weeks and plan to re-enter the US using my current visa.

* What happens if my H-1B extension is approved while I am outside the US? If that happens, should I return to the US before the start date of the extension? Or should I try to get a visa stamp for the extension while I am away?
* Will the H-1B extension begin from near the expiration date or will it start sooner?