SC 2.4.4: Use of Title and ARIA Techniques for Supplementing Link Text

[frecann]

I have a question regarding SC 2.4.4: Link Purpose (In Context) and the status of H33: Supplementing link text with the title attribute as a Sufficient Technique.

The Understanding SC 2.4.4 document lists H33 as a Sufficient Technique:
https://www.w3.org/WAI/WCAG22/Understanding/link-purpose-in-context.html

However, the H33 technique document includes the following statement in the Description section:

“Because of the extensive user agent limitations in supporting access to the title attribute, authors should use caution in applying this technique. For this reason, it is preferred that the author use technique C7… or H30…”

Source:
https://www.w3.org/WAI/WCAG22/Techniques/html/H33

Given this, I would like clarification on the following points:

1. What specific “extensive user agent limitations” are being referenced regarding support for the title attribute on links?

2. Within current WCAG 2.2 conformance expectations, is the title attribute still considered a valid or reliable method for supplementing link text under SC 2.4.4?

3. Is the use of aria-describedby recognized as an acceptable method for supplementing link text when the visible link text alone does not sufficiently convey the purpose of the link?

Any clarification on how these techniques should be interpreted in current accessibility practice would be appreciated.