H1B Max out - PERM Pending - COS to H4

Can anyone please help me here my H1B maxout is 13 April 2018 and PERM is pending for approval. My H1B visa and petition is valid until Sep 2019 (though not useful at this point). My employer is giving me an option to convert to H4 and upon I140 approval, change status back to H1. Also there is an option to work from India. The are anticipating ~3 months for PERM and I140 approval. Can someone please suggest which is the right option to choose? I am trying to understand what will be the implications in either options. How soon should I change my status to H4? Can I apply for EAD based on my spouse when we apply for H4. Incase of my PERM or I140 delay, can I work on EAD?