I did not get what you meant - 回複：求XBT, Pjiang!哭求幫助！公司是不是欺負人？H1B

What kind of paper work are waiting for you to sign? Company internal papers or USCIS docs?

If they're eager to have you done internal paper, they should take care USCIS form as well.

If they're I-129, go ahead sign it and then move yourself to B.

If you don't have I-129 done and start to work for B, it's a violation but it would not hurt that much if the paper is followed in near future.