What is your 485 RD? Based on recent posted on this board, it seems 485 processing time became much longer in 2019 than 2018. I suspect some local USCIS offices have much longer 485 interview backlog. In other words, it is possible that your 485 interview may not happen within 6 months from your 485 RD, especially at large cities with more people waiting for 485 interview. You need to confirm with the lawyer whether the company will provide a J form for your 485 interview if your change your job within 180 days but your interview is scheduled after 180 days.