PERM Location vs H1B Location

[rohanv1]

Hello experts,

My I140 was approved from location A(HQ office)and I am working at location B currently on H1B(our branch office) and working here since last 10 years), its same company and same job description and position at location A is still valid. My priority date is Dec 2, 2011. Now my Filling Date is current (Based on Eb2 to EB3 downgrade) and my Final Action date is still in future. I would like to file for I485 before the Filling Date retrogress.

Do I have to move to location specified in I140\PERM at the time of filling (and file and H1B amend to add location A before I485 filling).
If I do not have to move now, my understanding is that I will have to move and join at my PERM location as soon as get my EAD based on I485 filling. Is my understanding correct?