It might be OK if they could already get "single-factor authentication" to work. Trying to login to the BA website is fraught with difficulties, with one or more of the following occuring randomly.
The login link is no longer present.
The login credentials are not recognized even though they are definitely correct
After login you get a message along the lines that the systems are overloaded, try again later (a bit like when you try and phone)
The login goes into hang mode with BA's equivalent of the egg-timer (the moving bar in the middle of the screen)
Maybe they should try and fix these problems before venturing into something so complicated as 2-FA?