Travel Outside US - H1B extended successfully -> stamped visa expired -> h1 transfer

[h1bmess14]

Hi folks,

Looking for your expert advise.

My situation is:

I'm working with employer A and Recently got my H1B extended but visa not stamped yet. Old stamped visa is expired.

If I have an offer from employer B and start H1B transfer in regular process (Premium being suspended till 19-Feb-2019).

Say, if I decide not to join employer B until h1b transfer is approved.

1) Can I travel to India (going for stamping will be mandatory) while H1B transfer is in process with new employer B ? I will have employer A's approved I797.

2) If I can travel to India, will I be using last approved petition (h1b extended one) for stamping? or receipt notice of new h1b transfer ?

If I decide to join before H1B transfer approval:

3) What would happen If I travel to India in this case ?

Thanks in advance.