This is definitely the best set of rules that I have seen so far for an osr/nsr rpg that also integrates a framework for solo gaming. Without a doubt going to be my solo rpg of choice for quite some time since this game fundamentally contains rules from some modern osr/nsr rule sets that I love (Such as abstract distance) with all of the fundamental procedures you need to solo this type of game (especially dungeon generation).
As far as feedback, if possible, I probably would add maybe one more page for the wilderness section that would contain some expanded examples for the discovery’s you can find. That being said, this is pretty much just a nitpick since, for example, if I needed a specific landmark, I can roll for that in one of the games you mentioned as attributions (such as maze rats or the upcoming knave 2e). This would also give you that nice two page spread to make it consistent with some of the other sections in the book.
Hope more fans of solo gaming discover this game so that it gets the attention it deserves.