H1B Transfer while stamping is already scheduled for current employer in September

[avlesk]

Hi,

I am working for employer A and have approved I-140 with them. My current H1B is valid until 2019. I have scheduled for a dropbox and planned my trip to India from September 1st week to October 1st week.

Now, I got an offer from a new employer who is willing to transfer my H1B. It is a pretty good offer and I don't want to miss it. Since H1B premium processing is not available, what are my options?

If H1B transfer is filed before I leave the country in September, can I still go ahead and do the dropbox in September with employer A petition when H1B transfer is still in progress?

 

P.S: I can't cancel my India trip as I have legal obligations in India to take care during that time.