Well, the immediate initial test failed for me: I thought, "why not apply this on one of my own sites, where I have a sort of journal of poetry I've written?"...and there's no category for "Poem", and the request to add Poem as a type [1] is at least 9 years old, links to an even older issue in an unreadable issue tracker without any resolution (and seemingly without much effort to resolve it), and then dies off with…
Having worked in this field for a bit, this uncovers an even more fundamental flaw: The idea that we can have a single static ontology.
When I started to use LLMs I thought that was the missing link to convert content to semantic representations, even taking into account the errors/hallucinations within them.