More on not using Screen Magnification as an example

 The reason screen magnification does not belong in the new
 Accessibility API Mappings 1.1 document is because the primary
 functions of screen magnification and the accessibility APIs are
 disjoint. Screen magnification works just as well on a bitmap as
 it does on a WCAG 2.0 Level AAA document with perfect ARIA.

I am fully aware that modern screen magnification software uses
some features of the DOM supported by WCAG 2.0. These are mostly
used to enable vertical navigation.  I have not experienced any
evidence of screen magnification vendors using ARIA, but maybe
someone knows more on this.

The main point is this. The primary work of a screen magnifier
is enlargement with very intelligent curve smoothing.  While
this requires really smart programming the same effect can be
achieved with a closed circuit TV.   Screen magnification has
no place in a document about APIs that support assistive
technology. CCTVs and magnifying glasses are  just as relevant
screen magnifiers in this context.

In fact, magnfying glasses and closed circuit TV is just as relevant as
screen magnification within the entire context of WCAG.  WCAG is
unnecessary for screen magnification to work.