H1B premium processing with H4 extension through 2 employers simultaneously

Hi,

  • My H1B extension and dependent’s H4 extension filed this month by Employer - A in premium process.
  • After 1 week I got an offer from Employer - B and H1B transfer to be filed in premium and planning to file dependent’s H4 extension as well.
  • Both H1B will be filed in premium within 1 weeks difference.
  1. Is it suggested to file the H4 extension with both H1B applications?
  2. If both H1B applications are approved, How will it impact our H4 application?
  3. What do we need to do to continue H4 for the H1B where will work and no longer want to continue another.
  4. Is it advised to not file H4 extension with Employer B and file it later once H1B is approved? Can it impact H4 dependents in case the H4 approval remains pending for more than 6 months?

Appreciate your response.
Thanks in advance