H1B approved while on H4EAD, COS to H4 & EAD, previous EAD is valid can i use that

Hello Everyone,

I had H4EAD and my H1B was approved in Apr 2020. During this time I was on maternity leave with no job, hence filed COS H4 & EAD in June 2020. My previous EAD is valid until Sept 2021. My biometric is scheduled for H4 on Mar 9th 2021:

  1. Is there a separate biometric for EAD?
  2. While expediting what should I expedite H4 or EAD or both?
  3. if my H4 gets approved before EAD, can I used my old EAD card which is valid until Sept 2021 for my job?