Realistically, what Google will do in such a scenario is collect data about the illicit service, enumerate the devices the farm uses and what other activities the devices participate in. What you suggested has far less control over the devices that generate the attestations and it will show.

Also, if the implementation is competently done the phone will show the website for which you scanned the QR code. A user would be able to see whether or not that matches the site where they observed the QR code and proceed accordingly. In time Google will probably integrate it into the Chrome browser where a proxied QR code cannot even be shown.