H4 to H1B with approved I140 from previous employer

From 2013 till 2020 Feb I worked on H1B with company A and then resigned and shifted to H4. Company A revoked H1B in June 2020 but I140 is still approved. H1B validity expires on 1/19/2022. Recently started working on H4EAD with company B. Due to personal reasons now again I plan to get back on H1B -

Question1> Am I still Cap exempt? For how long after validity expires can I remain cap exempt?
Question2> Or do I need to go through the lottery?
Question3> Current employer (company B) is filing H1B under the lottery and does not accept my case to be cap exempt, will this impact my existing I140?
Question4> If I get picked in the lottery can I140 through company A still be used for H1b extension/transfer?

You can use AC21 for extension of status beyond H1B 6 year term based on approved I-140 till your GC date becomes current.

No.

If I were you, I won’t agree to do cap-subject as it doesn’t make any sense.

Yes, the ability to extend status beyond 6 years should still hold true.

Thanks Kalpesh,

Regarding Question 3, if they still proceed with lottery then is applying for PERM and I140 another one years wait? When can I ask them to port PD?

Thanks,
Vatsala

Employer can apply PERM immediately after you join, there is no need to wait.

This will be when they apply for I-140.