I've heard conflicting reports that QR codes aren't being used in Victorian venues as they "aren't compatible with the State's contact tracing system". I did see a venue on a tv news service this morning using a pen and paper. Surely that's not the norm given the last 6 months in Melbourne.
Having used QR codes extensively during the last 6 months including two I set up for sporting venues, it would astound me if they are not being used in Victoria. They are effective, efficient, simple to use and and a simple way to encourage patrons to record their attendance.