The QR method leak or whatever came from a reliable member who is close to GW and has access to the closed beta for quite some time AFAIK. The exploit is described pretty much as smealum's Ninjhax - so you scan the QR code once and you have it stored in the Mii maker for further offline use.
Its in private beta test. Nothing more to say about that. Even so releasing a public beta that can potential disrupt mii maker is not something GW would like to happen. Continue to keep stating this over and over will just result in more people getting pissed that nothing is being worked on for the N3DSXL when infact it is.