xtemplate proposes 'objects,' but are they really objects? How can they be extended to become 'true' objects?

xtemplate proposes 'objects,' but are they really objects? How can they be
extended to become 'true' objects?

In chat, @cgneider just pointed me to xtemplate after poking around my own
startup ltx3obj. In section 3, the documentation states (at the time of
writing):
An object type (sometimes just "object") is an abstract idea of a document
element that takes a fixed number of arguments corresponding to the
information from the document author that it is representing. A sectioning
object, for example, might take three inputs:
"title", "short title", and "label".
But isn't this just a data structure at that point? Wiktionary defines an
object as an instance of a class, and it defines a class as
A set of objects having the same behavior (but typically differing in
state), or a template defining such a set.
Thus, objects have state and behavior, which I clearly put forward in
ltx3obj. I find it difficult to believe that xtemplate does not have a
means of specifying behavior for a class (or object). Unfortunately, I
can't find any explicit support other than templates, which actually do
the work of defining what an object is rather than just saying it is.
Moreover, templates do not (in a way that is immediately obvious) support
methods.
So in conclusion, I have three very closely related questions:
Is there a way xtemplate can be extended to include this?
Does xtemplate already include this functionality, and is just non-obvious
about it from the outside looking in?
If not, are there any plans to officially include this functionality?