nvUltra is the successor note-taking app to nvAlt by Brett Terpstra. The app is still in beta and only downloadable for specially selected beta testers. Nevertheless, the manual is available online.
I started looking through it (https://nvultra.com/help/features) and came across the Connections feature. This what it does:
While working on a note, it may be helpful to see other notes on the same topic. That’s where Connections come in. When you toggle Connections mode, the entire contents of the note you’re working on are compared against the contents of all your other notes. The file list will show the notes with the most similarity and you can navigate them with the mouse or arrow keys.
Now that would be very useful to have in Obsidian, which would be an additional tool to Freelinking.