Bandersnatch is not really gettable as an mp3, you need actual Netflix for that. It's because the movie is not linear, it contains interactive elements with a lot of backing up while still remembering the choices you've made. It's more like a choose your own adventure film game, rather than a normal movie. True, you can watch the whole 5-hours-long master, but it's not worh it IMO. It's like listening to a band practicing in the studio instead of listening to the whole album. Fans will want to do this, most people won't.
There are graphs of it mapped out graphically, so you can watch, make choices at the right points and jump to the specified timestamps. That would be very hard to do for blind people, especially that most of those maps are in picture form. If someone wrote a program for that, sure, but I don't think anyone will.