I'm not sure what's the linklist implied but in original post I meant that a user potentially can extract the text from a pdf, highlight it and link a separate note for each highlight.
Here's the example:

A note with pdf (let's call it NoteTOC) keeps text extract from the pdf. In mind map view NoteTOC represents a TOC of pdf highlights. Each highlight of text in NoteTOC has a child note (backlinked to NoteTOC).

mermaid-diagram-20220208235137

mermaid src
graph TD
 subgraph NotebookPDF
 Highlights --> Child1(Child note1)
 Highlights --> Child2(Child note2)
 Highlights --> Child3(Child note3)
    subgraph NoteTOC
Pdf --> Text(Text from Pdf) --- Highlights
    end
 end

Preview

This way each highlight in pdf can be linked anywhere within the note structure (well, sharing externally is also possible). Also, you get the opportunity to comment each highlight in its own note.