I don't know however, why don't you simply apply for VOS and take the receipt during the interview to be on the safe side and show it when asked. If you get VOS before interview, take it during the during and show when asked.i agree and i ordered VOS. However i am a bit concerned for the interview but if they don't require it in the application why would they ask for it in the interview.
This way you will have at least peace of mind.