EB2 to EB1 w/previous employer

[SKG0909]

Hello Friends,

Here is my case and I would love to get this group's thoughts.

I moved from India to US as a Manager on H1B with Company A. I transferred to Company B few years back and Company B is filing my I-140 under EB2 category (Company A never filed I-140/GC).

1. If there is an opportunity to move back to my previous Company (i.e., Company A), will they be able to file I-140 under EB1 category? 

2. Should I wait until I-140 is approved (+180 days) from Company B before making the move? 

Thanks in advance!