Coask J1 file 140

I applied J1 waiver, the school does not sponsor H1 for next year but they can extend my current J1. If I file 140, once it approved, it means I can not extend J1 again. When I file 485, I will be required a new J1 waiver although I continue to work in the same project, same boss? If I need get approvement before I file 140 and 485? Is NIW or 485 still need document from school?