Filed for H1 from 2 employers

I filed for H1 from 2 employers[consultancyA and B] as my full time employer refused to do so.
Both of them got picked.
I received a project via 1 employer [employer A] and started working with them recently.I have filed for PREMIUM processing via employer B and got an RFE.

My stem OPT ends in July and my cap gap has been approved and has my Full time employer’s details on it.
I have these questions:

Can i fill out 2 I983 forms for these 2 employers [A and B]?
Do i need to fill out a new cap gap form for new employer? [A and B]?
Is it legal to work for both A and B employers at same time?

The I983 form should be for the company that you are currently working and going through OPT.
No, it is just one, does not matter, who it is. You can show the current receipt from the employer that you plan to work with and get the cap gap done.
Once you get H1B, usually, you work for one…but, you have a choice to also work for other under concurrent H1B. Check with attorney.