H1B Transfer approved, Still with Old employer and visa drop box with old employer?

My H1b Transfer has been approved and i am yet to join new employer. I got transfer approved for lesser duration, so i am thinking whether to join new employer or not. Also i have India travel plans this month end where i need to go for Visa stamping - Drop box.

Having two approved petitions, Can i do stamping for my current employer?

Any similar experience?

Thanks!