This is very important. If it got approved, then it is very safe to go back with AP, otherwise, once your I140 get flunked, you will lose your status and have to go back to China.
If you got your I140 approval already, just waiting for the I485 to be approved, then it is more than okay to use AP.
If you got your I140 approval already, just waiting for the I485 to be approved, then it is more than okay to use AP.