MyTwoCent and XiaoBaTuo , Help to evaluate the situation 140/485

Hi All, really appreciate the great support on this forum. I guess everyone got inspired by your guys to be some support whenever possible.
I need the help to evaluate the situation to switch employer with PERM EB2 LC and 140 approval and waiting for PD to file the 485.The pervious employer has agree to keep processing the case.(doubt?), besides the transfer is based on the H1b extension after 6 years period with the approved LC or 140 from pervious case.
Question:
What will be the negative impacts on the future process of 485 on pervious case, anything needs to be done to correct that.