Extension RFE

Hi, I have applied H1b extension as my visa expires on September. I have got RFE. Extension has been raised under Project A in Eastern Zone(filed at Vermont). My Project A has been completed and am moving to project B in central Region.

I believe the RFE will be filed now with new project.Could you please let me know in which data center it will be filed whether in Vermont again or in different DC’s. COuld you please confirm for which location it will be filed and how may day it will happen to process my file post filing RFE. Suppose if am filing my RFE on Sep 15, when i can expect next update.

When we can expect Premium process to be opened?