863211, At what point, the H-1 transfer will cancel the old H-1?

A further question,
Based on last action rule, old H-1 will be invalid upon the approval of the H-1 transfer, not from the starting date set in the H-1 transfer I-129, am I right?

It seems much simpler to use EAD rather that to transfer H-1. I understood that the benefit to keep H-1 is that one will not have to stop working and go out the country if his I-485 gets denied.However if the his H-1 is granted beyond 6 years limit based on an approval I-140, does he still need to stop working upon the denial of his I-485?

Thank you again for answering my question.