回複：回複：像我這樣，485遞交180天後可以換工作嗎？

If your I485 got denied, you are out of status right away, unless you can get H1 immediately, but due to H1 quota, you might not able to get it, also, you are not able to get F1.
GC usually always be higher priority than job security, unless you do not really care stay in US for long term.
Also, you need think about how job secured in B company. Even A company is not secure, the longer you stay, the less risk you take for your GC, maybe?
If you really like to go with B company, perhaps that is a workaround, ask B company for filing Perm/I140 for you after you join, after you get your new I140 approved, file another I485 based on your new I140 with your old PD ported? (I am not sure if it doable or not, maybe you can check with lawyer)