H1-B stamping via dropbox in India: please help

Hi, I had my H1-B dropbox appointment at Chennai VAC a couple days back. For my appointment, I had selected on the usvisascheduling website to pickup my passport from Bengaluru VFS after the visa is processed. I needed small help with two questions:

  1. How long is the passport held at a VFS for pickup? What happens if I’m not able to pick in time?
  2. Is it possible to change the option from pickup at VFS to delivery at my home address now?