I did an early walk in for my biometric appointment for my N400, because by mistake USCIS sent me to my older State, which is about 4 hours from where I live now. So I attempted an early appointment to see if I could avoid the drive, and missing one day of work. Alas! It worked. I went to my appointment first thing Monday morning (I was at their parking lot at 7:30 am) and they let me in. I did tell my supervisor at work, though, that I did not know if I was going to come in that morning because this appointment was very important to me. As others have stated, without your biometrics your case will be denied, and then later on you might be out of status, so your job might gown down the sink as well. Not worth it!