Here are my 2 cents :
Based on the initial data available for multiple I-485 applications scenario , there is a risk of the second 485 getting transferred to the service center where the original 485 is.
Heard of many cases on telegram/trackitt. However, I am not sure if the I-140 status matters. I think most of them had the EB3 I-140 approved.
The service center differences are real. It shows in the Q4 data released by USCIS. NBC is processing at a much faster pace.
In quarter 4 of FY2021, the USCIS approved 86,704 EB green cards in total.
* SRC approved 5,968
* LIN approved 4,622
* NBC approved 76,114
They all start FY22 with the similar backlog.
* 89,002 are at SRC
* 83,574 are at LIN
* 72,914 are at NBC
Source:
https://www.uscis.gov/sites/default/...y2021_qtr4.pdf
At some point USCIS will act and transfer those cases but there is no indication of that happening anytime soon.
If it was me, I would seriously consider withdrawing the LIN application with the hope that it helps keep the second application at NBC. I heard of some cases where the second application stayed at NBC after the withdrawal of first application.
I would suggest doing some more research on this. Follow the relevant trackitt/telegram groups.
Worst case with the withdrawal is your second application still gets transferred to NSC. That means you might loose 2-3 months in the queue(by the RD).
It may be worth taking a chance considering how the processing times differ between NBC and LIN.