H1 B extension question and further studies

[Lattelite]

Hello,
My husband is currently working and is in his 4 th year of H1 B. So he has 2 years for the H1-B 6 year cap. He has not started his green card process yet and plans to do so. However he is also interested in doing his Phd which he plans to do part time from next year. So here are our questions

1) His phd will take another 5 years, and in this time his greencard process will be done by the current company he is working at. Say his greencard process is not completed by the time he graduates. His h1-b visa of 6 years is now expired and he has a h1b visa extension then in this case, can he leave his job and take up a new job as per his phd degree?

What happens to his greencard process? or is he even valid to have a H1-B visa now

Thanks!
Tc.

[sk4ih]

If H1 is extended, the job duties should be similar to what was mentioned in original H1 petition.
GC can be continued. H1 beyond 6 years can be extended only when Labor is applied and 1 year is passed.