You should submit PP request together with your response to RFE otherwise it
takes forever to get it approved. It takes me one year to get my Eb1a 140
approved since I did not PP with my initial submission and the response to
RFE. USCIS said I would get information about my case in 2 month after they
received my response to RFE but it did not happened. Finally I filed PP
request 3 month after my response to RFE pending and got another RFE because
the IO was changed and he did not have my response package.I have to submit
my response again and fortunately get it approved within 2 weeks.