> Any kind of flow to handle these scenarios is basically going to look a lot like how it looks now: Keep emergency recover codes that the user has to print out and use as an extreme emergency, etc.

The worst problem: these recovery codes are not protected from government seizure or theft. A password? I can keep that in my head and, sans government-planted keyloggers or tactical use of a wrench (https://xkcd.com/538/), the government or thief doesn't stand a chance.