HText HTML element callbacks

I am finally back to looking at the HText interface, particularly
the usage of the callbacks.

In looking at the callbacks for handling HTML elements,
HText_beginElement() and HText_endElement(), they appear to be
a means for providing counterparts to HTML_start_element() and
HTML_end_element() in HTML.c.  But these two routines are invoked
by way of
    SGML_write() calls start_element() calls HTML_start_element()
    SGML_write() calls end_element() calls HTML_end_element()
Thus, to get at these by way of callbacks, I would have to provide
my own customized SGML.c as well.

Have I overlooked something?  It seems like it shouldn't be necessary
to rewrite SGML.c in order to get at the element callbacks.

--Rick Kwan