Thank you very much. One other question
Do we need to withdraw H4 extension before leaving USA or it can be done even later after reentering the country?
Withdrawing H4 will impact your EAD application which may get denied, so I wont touch it before leaving or after entering if I were you. If your EOS & EAD application is still pending after you enter the US with new I-94 issued by CBP based on visa stamp, you can send the copy of I-94 to the USCIS center processing your application using interfiling process.