Can H4 work on I485 EAD and later work on H4 EAD after getting H4 stamping?

[H1l1]

My H1 is approved till 2024.
My spouse H4 is expiring on June2021, we didn't apply for her H4 renewal as she got approved her I 485 EAD and AP card.

a) Can spouse(H4) work on I485 EAD and not apply H4 renewal? What will be the status for H4?
b) Later this year, once she travel to India, can she get her H4 stamp based on primary applicant H1? 
   After coming to USA on H4 status, can she continue working on I485 EAD or do we need to file H4 EAD?
c) Some people suggesting to not use I 485 EAD because what if in worst case I 485 get denial.
   Can spouse (H4) go back to India and get her H4 stamp at that time and come back to USA or will she face any out of status questions?

Edited May 6, 2021 by H1l1
date correction

[pontevecchio]

Do not listen to such people. She can work on the basis of the EAD/AOS based.

[ParDesh99]

Hi,

I will like to expand on the original question a bit. Here is my situation:

- We filed for H4 and H4-EAD for my wife along with my H1-B extension back in June 2020.
- My H1-B was approved until 2023, but no updates were received for H4/EAD case. The H4-EAD eventually expired in Nov 2020 and my wife had to leave her job
- In the meanwhile, the Date for my approved I-140 became current in Oct 2020. So we filed I-485 for both
- We had our finger-printing appt in 1st week of Dec.
- My wife had to travel to India on family emergency in 2nd week of Dec. while the EAD/AP application was still in progress
- We received EAD/AP for both of us before the end of the year.
- Wife returned from India with a stamped H4 visa in March. She could also start working using approved EAD (AOS) in April
- We have now (June 2021) received an approved H4-EAD (765), but also received a Denial for original H4 (539) application submitted in June 2020, since she already has H-4 visa stamped (reason given).

Q1. Should there be any problem (anticipated) for I-485 processing for my wife?
Q2. Can she continue to work using EAD (AOS)? Or should she switch to using H4-EAD instead?
Q3. Do we need to file a secondary I-485 for my wife?

Please advise.