I got my I-140 approved with employer A. I am still with him. My priority date is Jan 2012. Per my understanding I get to retain my priority date for my lifetime. If I switch to employer B and if he delays PERM/I-140 filing or even if he files, during the process, if the EAD for I-140 rule kicks in, will I be eligible for EAD based on my approved I-140 with employer A, while still working for employer B? Do I have to working for the same employer A that got my PERM / I-140 approved? Is it possible to switch back to employer A just for the EAD, assuming they take me back?