I recently used linked thinking in Obsidian to do some critical meme analysis for therapy. It was a good exercise in creating index notes, e.g. a meme crossing over Marvel and The Good Place wouldn't fit in a folder for either one.
I'm not sure if it counts, but I've been using Joplin for a couple years now to keep notes on various things in my life, ranging from gaming/movie logs to how to properly install some self-hosted service on a NAS. I'm curious to learn more about PKMSs though.
I would say that counts! Is there anything specific you're curious about? Particular issues in your personal system or interesting things you've seen from others?
Sorry for the delayed response! No particular issues, just interesting to see that there’s a name and a community for this kind of system, and even that there is a system!