Is that ok if i appear for a fresh h1b visa stamping while i already have a valid stamp from a different employer

Hi - I have a query related to h1b stamping. I am currently working with Employer A in India who has filed a petition for me .Also, i am holding another job offer from employer B and my visa got successfully transferred to Employer B and last week his visa got stamped. However, the petition that my employer A has filed ,got approved today.

–Now i am planning to continue to work for employer A and would like to get fresh stamping for employer A, can I do that? I know since i am already holding valid visa, i can travel using that. But my employer A would require stamping on it’s name to raise my travel request.

Will that be risky? Or in such cases, visa officer will freshly stamp with employer A and cancel stamping which i already have with employer B?

In case, they do not stamp my visa for employer A , can they still cancel my existing valid visa which i am holding with employer B?