But rather than just section headings, perhaps complete sentences that you could "zoom-in" to more detailed wording. Or if things seem to be too detailed, you could zoom-out.
Seems hard to automate. Better writing could probably solve a lot of my frustration (not for this article though).
An ideal application would be for educational material (such as this post). Where it's worth the significant human effort to craft the multiple variants of the subject.
(e.g. Sesame Street is... (More...) - > Sesame Street is a children's show.)
Also, each sentence could be an object of sorts with one value for the simplified version and references to other objects that constitute the detail of the simple sentence. The referenced objects could be of the same class, and, in turn, resolve to even further detail by reference.
The pitfall is, of course, that it would require some extra thought while writing to keep everything cohesive and sensible with varying levels of complexity on the page at the same time.