No, its a shitty way of doing it that will never work in practice.
Nobody will remember where those are.
They will likely download the pdf, store it in downloads, where it will be used by some Trojan to hijack their account, or they will lose it during a device switch or some dataloss event.
Telling people to store one time codes securely and reliably, for every single account they own, and telling them that will only work for the services that bothered to add that on to their implantation of the standard, works for techys, but not the overall populous.
Nobody will remember where those are.
They will likely download the pdf, store it in downloads, where it will be used by some Trojan to hijack their account, or they will lose it during a device switch or some dataloss event.
Telling people to store one time codes securely and reliably, for every single account they own, and telling them that will only work for the services that bothered to add that on to their implantation of the standard, works for techys, but not the overall populous.