This is one of those things that looks interesting to me as someone who enjoys security topics, algorithms and the like. I can see digging into the source code/reading about the techniques involved because I want to know how it was done. But I am struggling to figure out where something like this would be useful -- is there a threat model where this would be useful as a "layer in the onion" of things protecting sensitive data or a way in which this would be superior for a use case that isn't already solved better by something else?
Even the author kind of jokes about an old diary password vs remembering enough hiding places. I think the latter would be a much bigger problem from personal experience and would require having fewer parts and more hiding places, eroding the provided security in the process[0]. :)
Multi-sig comes to mind, but my only exposure to that is "having to participate in it" by "putting a USB key in and running a program along with two of my coworkers" in order to push the one update we ever pushed with that tooling. I remember we all had to provide our keys and "if I was out sick, no update was going out" but I'm not sure if that was a limitation of what we were using or if we just set them up that way because it was "alpha" at the time.
None-the-less, very interesting!
[0] I can imagine, though, that "under the mattress" would be the equivalent security to setting your password to "password".