xiaobaitu and experts: I-140, please help!

I have several questions about I-140. My attorney has not received the certified PERM and had filed I-140 application with request duplicate copy after one month of PERM approval. He also told me I can not file 485 until I-140 approval.
1. Will it take longer time than the application with certified PERM?
2. Why does the attorney not ask the duplicate copy by himself?
3. Is there a max number for asking the duplicate copy?

Thanks so much.