Comments on "Use Cases & Exploratory Approaches for Ruby Markup"

I am puzzled by 2.1 Accessibility use case in
"Use Cases & Exploratory Approaches for Ruby Markup".

https://www.w3.org/TR/ruby-use-cases/#accessibility

First, please provide a link to the research by the
Japanese government.

Second, as far as I know, some dyslexic people have
problems with hiragana and ruby.  They can read
kanji.  I thus just cannot believe the content of this
subsection.

Third, low-vision is completely ignored.
-- 
Regards,
Makoto