This is a little anti-modular, but I am frequently having a situation where I want a transcluded child's children to not appear in the outer table of contents. For example, on my funding and grants page, I do not want the tree of each grant page to appear in the TOC. Likewise, I have the same issue with my blog.
I have a similar situation, but for queries. Now queries will transclude the trees in full, which might cause heavy burden on the browser as there are lots of diagrams and dynamically rendered contents.
Specifically, I would like a "enhanced" link style transclusion for the query result, so that the contents are not transcluded, yet the front matter are transcluded, as showing titles, authors, dates etc. are still desired. Maybe it's a separate issue, but I happen to see this issue with certain relevance, as this maybe implemented as a transclusion option, completely decoupled from queries. This could be viewed as a transclusion of depth 0.5 :)
That's an interesting point, I have wanted something like that too. Can't say when we will have such a feature, but I think it's a good idea.
Yeah. So far, I'm able to bypass the browser burden thing by transcluding an intermediate tree, which includes links to the query tree. And I've even implemented lazy loading so that they are not a burden when they are in the backmatter (e.g. of the intermediate tree).