If in a (K2) category description (see attached example) the heading tag is changed, this is not taken into the html code, see page details at http://www.wind-rose.co.za menu "Accommodation" which lists the category "Accommodation" and its description. I have changed this heading 2 but html shows <h1 class="item-title">Accommodation</h1><p class="item-desc">Spacious rooms (>50m2) with where I would expect h2 class instead of p class ="item-desc" etcetera.
I would not make a point of header tags if they are not so important for SEO.