[bevr1337]

Oof, yes that's certainly a way QR codes can go wrong. Ideally manufacturers print the QR code on the device such that it lasts the device's lifetime.

It would be nice if technical users (installers) could reset the certificates or keys too. Besides losing the QR code, secondhand owners also want some assurances.

[luckydata]

exactly, this scenario is why I'm excited about bluetooth provisioning.