Have I-797 and not traveled wish to transfer H1 to new employer?

USA H1B Visa
1

Hello Everyone,

I have valid H1B approval till September 2019 or say I-797 approval notice that was filed by employer A and I never traveled to USA on H1B status for employer A (As my Visa not get stamped because he did not have any opportunity for me for now), and the employer B with whom I am working in India wish to transfer that H1 and want to send me USA. Please let me know following

  1.   Is employer B need to file new cap exempt petition?

  2.   If yes for ques 1, how much time this would take to approve?

  3.   Fee required to file new cap exempt petition?

  4.   In case if petition from employer B not approved in that case H1B petition from employer A will be considered as approved or not?
2 
  1.   Is employer B need to file new cap exempt petition? - Yes

  2.   If yes for ques 1, how much time this would take to approve? - Premium would take 15 calendar days and for normal processing please check USCIS processing times. (usually months)

  3.   Fee required to file new cap exempt petition? - Yes, because someone in USCIS is working on your case and the beneficiary is not supposed to pay (except Premium processing fee if the employer demands.)

  4.   In case if petition from employer B not approved in that case H1B petition from employer A will be considered as approved or not? - Employer A's 797 would still be valid until the time they revoke.