H1B amendment possible issues

[checkvisa]

Hi, 

My wife working with employer A since 8 years with some overall bench period of 8-10 months on and off  all this while and has approved i140 

now since past couple of weeks she was on bench as she was not keeping well partly and partly she had to take care of her parents.

now she has got a confirmation on new project from new client. Her employer A is now not ready to file amendment, he is instead saying she should find another employer to transfer her H1.

i have confusion here:

1. Employer A is concerned about her new project amendment filling, he is saying since she is not having time sheets for her bench period, he cannot show documents if there happens to be rfe about her past 2-3 months work. Please suggest if this is valid reason or there is any work around?

2. Say if she somehow starts filling amendment for this new contract. Can it be possible for her to transfer visa to another employer B during this amendment with Employer A process?