The small footprint quirc QR decoding lib has merged some fixes that makes it way more reliable when scanning flipped QR codes. I merged these fixes myself to opmsg-qr (which forks quirc), so its in turn also more reliable when scanning opmsg QR-code keys sent via phone messengers. Give it a try! Painless opmsg persona sharing via Signal and such. Still recommended to use camera with auto-focus. Scanning QR codes with opmsg-qr however needs some seconds, compared on what you experience by scanning with your phone. So, just experiment with it to get a feeling and how it could be useful.