Hi,
FBI security check would be done within 3-4 days for about 80% of all 485 and within 2 months for other 10% and longer than 6 months for last 10%. Only speaking of eb2 485 Texas with 140 approval through premium, for 80% cases, 485 might be approved within 1 week or 5 weeks since more recent one between 140 approval and FP. For other 10%, it might take about 2 months more than normal case. In the last 10%, people might need much more patience.
It's just my thought.
Good luck!