That was my disclaimer, but I do prefer, regardless of what works on GrapheneOS, having a QR in my invoice letters. You could shine a light on the envelope and likely read it without opening, but having anyone be able to touch their phone to the envelope to see I owe Y$ to X sounds worse. It's also nice in email since there's less to copy over, and my PC doesn't have NFC.

I'd only prefer to have NFC over QR for in-store payment, and I transact way less money per month in-store.