That is a risk. But since I never has a CO I knew about but now have a visa I'm glad all paperwork was submitted. All be it the medical and police checks went in some months after the rest of my paperwork. Quick calf if all 40+ thousand 820 visa applicants do what the department recommends and submit their medical straight away then twelve months later have to resubmit. How many million dollars in un necessary medical charges does the Australian immigration industry make.