Generic CT proposal text:p/text:h and ac:change

Hi,
  Looking at the generic change tracking proposal, example 6.13.2 uses
delta:remove-leaving-content-start to handle the case when a text:p is
toggled to a text:h in revisions. Example 6.9.2 uses ac:changeXXX to
track an attribute's values during a document's lifetime, in the example
the text:style-name is tracked.

  How do these two interact? If I set a style to a heading then the
document will need to move to using a text:h and thus will use a
delta:remove-leaving-content-start to include and strip the original
text:p before outputting the text:h for the current heading style.

  Should ac:change attributes be used for inclusive groups which do not
require mutation between text:p and text:h elements and the
delta:remove-leaving-content-start method used when such an element
change has been forced?