Amendment and H1B transfer on Premium at same time

[srinivas347]

I am currently working for an employer A with valid approved visa and recently joined a new client X one month back. My current employer A has filed an amendment petition on Premium processing with USCIS and yet to receive the receipt copy and pending approval.

 

Also, at same time i got another opportunity to work at another client Y through different employer B. Can employer B file H1B transfer petition on Premium processing while the current H1B amendment application is filed and currently under processing by USCIS. 

 

If it is possible to do the H1B transfer, can i use my old I797 as supporting document for H1B transfer with new employer. Will there be any issues if the client letter is not submitted to USCIS.