RFE on fresh H1B. Can I responder through new petitioner?

I am on L1B. Applied for Fresh H1B with Employer ‘A’, and received RFE. Employer A is unable to get client letter. However, recently company B, offered to respond to my RFE with their client letter. Company B says they can respond to RFE with paperwork stating that they are taking me over as their employee from Company ‘A’. I was wondering if such change of employer will be risky for H1B?

This is not possible. The petition is owned by employer and not you. So a new employer cannot overtake the petition filed by A. If A’s petition gets approved, then B can file their own petition using A’s petition as reference (for cap-exempt purpose).