> Instead of an <appSpan/> wouldn't it be better to use <app> in the stand off
> manner documented at http://www.tei-c.org/release/doc/tei-p5-
> doc/en/html/TC.html#TCAPLN ?
> i.e. use @from and @to to point to the starting point and ending point of
> the app, by use of @xml:ids on elements there (e.g. <anchor/>) or xpointer
> schemes like xpath()?
For an external external apparatus, perhaps. I'm not sure that an external apparatus would be able to handle the case of say one and a half changed paragraph or other changes overlapping paragraph boundaries. (Except by representing paragraphs using milestone-like elements).