As a big fan of both FIST and Cultist Simulator/ Book of Hours, this impressed me. I like how it treats knowledge of the Hours/Longs in a winking fashion, rather than a prerequisite to comprehension.
The PDF has a bit of wonkiness that might not show up depending on the viewer used, but I'm getting unsupported bit warnings on most of the pages. It seems to be tied to a page wide image, probably a background? The whole Aspects chapter also fails to load anything. Again, might not be an issue on PDF viewers with more aggressive automatic compensation/correction protocols.