I tried to do a startup based on an idea like this, but it’s difficult because you essentially have to have keyboard input into the device, which means you now

I tried to do a startup based on an idea like this, but it’s difficult because you essentially have to have keyboard input into the device, which means you now have to trust the keyboard. And once you have a passphrase it is confusing as to whether you should make a 2FA device or a password manager. But it is possible, on a technical level, because embedded devices now have enough RAM to run “effective” versions of argon2 or scrypt or whatever may be preferable at this time.