The team is developing a mobile authenticator. In fact, it’s available now in beta form.
Get more info here!
I’m not sure off the top of my head of how using command line arguments would interfere with the use of the mobile authenticator; but that’s likely just because I can’t remember all of the command line options offhand ;-) If you find a combo that doesn’t work, please feel free to report it in the official feedback thread
For those who don’t have access to a smartphone, there are hardware devices you can purchase which support the same standard that we use. Just check for “OATH” or “TOTP” devices which comply with RFC 6238. Naturally, we cannot recommend or endorse any specific products.
Thanks to everyone who is helping other players with advice about this. And thanks to all of you for helping us test the Mobile Authenticator!