Can we schedule Dropbox appointment with receipt number alone while waiting for the approval notice thru premium?

My h1B extension got filed and got the new receipt number. I am planning for India trip after 2 months… Right now H1B filed in normal mode. But I thinking of booking the dropbox appointment now itself with new receipt number, approximate petition start date and petition end date inorder to get the dropbox appointment within my travel schedules.

After booked the appointment, I am thinking of converting the H1B extension to Premium, so that atleast I will receive the soft copy of approval notice before the appointment date.

Also created the new DS160’s with correct new receipt number already. Only problem I am seeing the approximate start and end date I added to the appointment portal.

I need your valuable suggestions on this? Will this approach is possible to do and get the visa stamped only based on approval notice? or is it something we can correct the dates later ?

I dont recommend your approach, however you can put the start date as the next day of your end date on current I-797 and end date of 3 years from the start date. Once you get the approval notice you need to submit a new DS-160 and then carry the old and new DS-160 to your dropbox appointment.