Hi,
I don’t know if I can help you, but I just use it like Ditto. Maybe I’m doing the opposite of what you’re doing, as I’m just pulling in the content of child documents and templating the result. What you’re doing sounds very advanced and slick, but maybe more resource-intensive?
I have a root document where I put this call:
[[getResources? &includeTVs=`1` &includeContent=`1` &tpl=`GetResourcesTest`]]
Then I just stick child documents under that which contain what I want. They could be thumbnails, slides, products, what-have-you. A user could just be instructed to make child documents under it to add more goodies to the root page display. Note that I’m also pulling in TV content from each page, which is entirely optional, of course. The good thing about a TV is that it could be limited to an image, or some other thing.
I have that call in page content, but it could be used anywhere in a template, and you can tell it to use whatever parent(s) or documents you want it to aim at by using a couple more parms.
But I’m guessing that I’ve missed part of your point.