H4 EAD with I-140 approved wanting to move to new employer

[PraveenKumar2021]

Hi… My scenario here is: I moved to H4 visa at the end of my H1B tenure… I was working with the same employer when transitioning from H1B to H4 EAD… my employer filed for I-140 and it’s pending approval…

Questions:

1. Once my I-140 is approved, can I move to another employer after staying for 6 months with the current employer? With H4 EAD? Or should I move to H1B (cap exempt) with my current employer, and then be able to switch to a new employer?
2. Will the 6 months period after I-140 approval kick in only when I move to an H1B visa, or does it apply when I am on a H4 visa with EAD? 
3. Being in H4 EAD with I-140 approved, can I stay with my current employer for 6 months, and then move to another employer with an H4 visa? In this case, can I move my I-140 to my new employer? And can the new employer file H1B (cap exempt) after moving?

Please let me know your comments so I can check and decide if I require premium processing for my I-140 and plan my move accordingly. Thanks.