H1B about to max out so COS to H4

I am an Indian and working on H1b which is maxing out on May 16, 2022 (including any recapture time). My PERM was filed on Nov 10, 2021. As I won’t be getting an H1b extension before the max out date( May 14, 2022) thinking to file for a Change of Status from H1 to H4 based on my wife’s H1B and staying in the US and wait for the PERM and I140 to be approved.
Attorney says they can file for an H1B extension after I140 approval and I would have to go to India and get it stamped to come back and resume work.

I had a few queries for the same:

  1. If I file for COS from H1 to H4 one week before the max out, I would be able to get an extension later when I140 is approved.

  2. When I remain in the USA with COS pending can I continue being employed with Leave of Absence with no pay. If I have to resign what should be needed at time of H1B extension/stamping to show an employer-employee relationship

  3. If the H1B extension is granted say in 2month’s time and COS to H4 is still pending, can I create new COS to H1 in premium (along with the extension?), or will have to wait for H4 COS approval. (Or travel back to India to get H1B stamped?)

  4. When I file a COS to H4 and stop working will my stay be considered as part of pending H4? So that I will have some days left in H1B max out at the time of an extension.

Also is flying back to India before 1 week of max out and waiting for an extension from India a better option than staying in the US with H1 to H4 COS filed? (Considering no visa stamping dates available in 2 ~ 3 months in India)

Thanks a lot for the help.