I'd like to share an idea. If you think that I don't know of what I am speaking of, probably you're right; nevertheless I'll try.
Labeled section trasclusion, I presume, simply runs as a substring search into raw wiki code of a page; it gives back a piece of the page as it is (but removing any <section...> tag inside). Imagine that this "copy and paste" of chunks of wiki code would be the first parsing step, the result being a new wiki text, then parsed for template code and other wiki code.
If this would happen, I imagine that the original page could be considered an "object", t.i. a collection of "attributes" (fragments of text) and "methods" (template chunks). So, you could write template pages with collections of different template functions,. or pages with collections of different data, or mixed pages with both data and functions, any of them being accessible from any wiki page of the same project (while waiting for interwiki transclusionn).
Then, simply adding carefully a "self-tranclusion permission" to use chunks of code of a page into the same page , the conversion of a page into a true,even if simple, "object" would be complete.
Alex