Consider roleDescription for 1.0
Raising roleDescription (currently in future work) as an issue b/c "role description" is in ARIA 1.1 and implemented on Apple's iOS and macOS platforms. For example, in iWork (native), we can and sometimes do use custom role descriptions for elements like "slide" (on a group or other container role), "chart" (on an image role), etc. Without this web feature, we would not be able to achieve the same end-user result in iWork for iCloud versions of Keynote, Numbers, etc. Inclusion of this feature on any platform seems trivial once the ARIA equivalent has been implemented.
If no other editors step forth with a +1, we'll leave it in the future work section.
Tentative +1
I'd actually lean towards almost everything in ARIA having an equivalent AccessibleNode property unless there's a good reason not to, like it's explicitly deprecated in ARIA.