Being chosen in the H1B lottery is significant. Most experts would like to change jobs earlier, so premium processing is being thought of as an option by them.
With premium processing, it is certain that USCIS will process the H1B petition in 15 calendar days. Quick processing, however, does not equate to joining the new company earlier.
Even if the H1B is approved in a hurry, the formal employment date is October 1. That means no one can begin working under the new H1V status prior to this date, even with premium processing. The rule holds for all H1B visa holders, and employers have to adhere to it.
Green Card Nightmare: USCIS Silent After Approval
For those wanting to change employers, another regulation makes it difficult. Typically, USCIS insists on at least one pay stub from the initial H1B employer prior to approving a transfer. That is, working with the initial sponsor and getting paid before one can even apply for a transfer.
Premium processing is beneficial for a quick approval, but not for an early job change. Job change planning requires proper timing to adhere to visa regulations and prevent issues.
The H1B process has precise timelines that can't be modified. Familiarity with the rules prevents errors and makes the career transition easy.