if your i-485 is pending more than 180 days you can use AC21 and move to new simialr job in west coast. if not and you won’t work on sonpsor company after GC, in theory your GC process is fraud, because you and sponsor company signed on docuemnt that you will work on sponsor company. You can try and see whether uscis will find out or not. They may or may not. However doing this you will break a couple of laws. First your sponsor company forge tax documents for you. (anyway your husband has to file federal/state tax which will show your west coast address, if you file jointly). Second as a foreigner in US, you are suupsoed to report your address change to uscis. Third you are not working on sponsor company. There is a good reason why lawyer said so.