I would really love to see this idea implemented. It would help A LOT. I would love to see concepts within notes treated as separate entities. I think this is the same as having sub notes. I want to be able to bi-link these concepts across notes and notebooks. I would also like to SEE the linked concept note /sub-note or even the note as a whole whenever I click on the link. This should appear as a side window and I should be able to edit it.
This is a very powerful way to implement something like the zettlekasten method in Evernote. I hope I will get to see this feature someday.
I would really love to see this idea implemented. I also need the links to be bidirectional. I want to see sections within notes to be treated as mini notes or like index cards (should I chose this route,not by default)