I'm not asking the WG or the W3C to endorse any vendor specific technology. For the guidelines not to include this as the primary mechanism for assistive technology to access document element information there would need to be strong arguements on how other techniques which are also cross plateform could acheive the same results more efficently or with better representations of the information. Remember these guidelines must be approved by the W3C member companies and checkpoints that are not plateform independent or refer to proprietary technologies when other W3C exist may have difficulty getting their approal. As soon I have more information, I'll pass it on.
Technique needs to gain acceptance by assistive technology developers.
It could be included as a technique in the technique document.