EBC2 downgrade to EBC3 question

     Sorry I could not type Chinese,  As current EBC3 is faster,  I want to dowgrade my EBC2 to EBC3. I just ask my lawyer,  he said for the I-140 I could not use the premium process, then I have to wait 4-6 months to get I-140 approval. Dose anyone have similar experience, could you give some information.  If the priority date is coming, could I submit the I-140 and 485 togather.


Thank you very much!