Approved I140 - H1 CAP Exempt filing timelime

[SRPUSA]

I moved from H1 to H4 on Feb 2018 with few weeks left in H1 6 year CAP. My Priority date is May 2018 and I got my I140 approved on Feb 2019. This is through Employer A with whom I am currently on Long leave. I recently got my H4 EAD approved(Jan 2020).
My queries are

1. If I join Employer B using my H4 EAD, is there any time frame within which I need to get my H1 extended in CAP Exempt mode using my approved I140 provided my Employer A doesn't revoke I140. Or I can wait until my priority date to gain my H1 status back and move further in GC process?

2. My Employer A doesn't share approved copy of I140. I raised FOIA request and all I received is the I140 filing copy with which I could extract my I140 receipt number, Alien number and ETA case number.
Does this information suffice for another employer to file H1 transfer for me or they need actual I140 approval copy?

[scientist2016]

1. You can stay i H4 as long as you wish. You do not need to be in H1 for continuation of your GC processing. Employer A cannot revoke your I140 now (since it has been approved more than 6 months ago). If you want to go back to H1, it would be a good idea to file a cap exempt petition before 2024.