Sounds like use 1.3 for me. Support standard output APIs so that screen readers can get text. If you only give visual feedback for UA messages, that's unacceptable. The more I listen, the more I think it's important to talk about redundancy. It doesn't make sense for a self-voicing UA to not be able to read its own menu.
Beeps are different from speech synthesis.
Or selecting a menu entry. 1.3 is about system standards. 1.5 is about redundancy of output. I have some. Difficult to understand.