As co-editor I often feel like the janitor of the ARIA specification. I tend to spend time on things that feel like going into the basement, full of stuff nobody remembers putting there, much of it questionable, and very little that can just be thrown out.
…This started out last fall and is mostly a quick observation on screenreader behaviors and turned into some meandering thoughts about "linearizable" SVGs.
…Links with complex content are a long standing accessibility challenge, essentially ever since HTML opened up the a tag to contain virtually anything else. Equation layout is not accessible and there is no single ARIA pattern that will help you make it so. So you need to adjust your approach as the situation requires - and, above all, as your users require.