回複：Thanks.So if I get

While I-485 pending, you lose J1 once you leave USA (including going to Canada or Mexico) and cannot re-gain it. You can only keep the existing and continuing J1 if you stay in US and maintain J1 status, which means working for your sponsor under valid DS2019/IAP66. So you will need the EAD (c9, based on I-485) to work (and no employer limitation) after you re-enter US.