Job change - i-140 on EB2

Hi, I have my i-140 approved with Employer A.
If I change my job to Employer B, then I am aware that B will have to start whole GC process again except I will retain my priority date.
My question is, without B starting my GC, after a couple of years, if I come back to Employer A (whose name is on my approved i-140), then will Employer A need to file my GC from scratch again?
its like the job sequence is: A (approved i-140) → B → A.
Please let me know.

Employer A will not need to restart the PERM process if they don’t withdraw the I-140 after you leave.

Yes they will not, as job change will be after 6 months of i-140 approval.
Thanks Kalpesh for your answer, this really helps.