Withdrawal of 221g application and applying for new one

I got my H1b approval in 2017 and attended Visa stamping after a month, But since I could not produce client letter I was issued 221g slip and my visa was denied.But the client letter could not be managed as the project and client has been changed.

My petitioner has suggested to withdraw the VISA application by dropping an email to the consulate about no longer validity of the project.

Queries:

After withdrawing the current application, will all the procedure be like the normal procedure or there will be some changes?

can we process amendment without the VISA stamped?

hi, got answers as expected ?
Please review my query and answer if you can help,