I'd love to see a table and CSV file of the Issue Impact (Critical/Serious/Moderate/Minor) issues.

Issue impacts are great https://github.com/dequelabs/axe-core/blob/develop/doc/issue_impact.md

But for people to adopt this framework (and abandon their own) it helps to have a simple, maintained list that allows people to understand how these issues are grouped.

I'm not sure how/when these are revised. Hopefully it is something that is updated by the core team from time to time as issues change.

However, it would go further if people could easily see what is bundled in the JSON files.