> I would be interested in any examples (and/or explanations) of what
> techniques and display conventions are currently used by the community
> for rendering addSpan and delSpan fragments that break tree structure.
> I'm primarily (but not exclusively) interested in HTML.
The TEI to Word stylesheets we maintain for ISO simply map to similar standoff elements in Word. That does not help you with Html, but it does show the tags are useable.