PERM Stll processing while EB2 Date is current

USA
, ,
1

If EB2 priority date becomes current (Final Action dates) while PERM by new employer is under processing. In such scenarios

  1. what can be done to secure and not lose my Priority date?
  2. Once PERM is approved, can I file I140 and I485 (assuming the dates are not retrogressed by uscIs)
  3. OR Is there any time limit to file I140 and I485 (assuming the dates are not retrogressed by uscIs) ?
2

You can file i485 only when date is current.
I140 can be filed anytime.