◾whether the exploration logs are sufficiently unsettling and hold interest
I'm not a fan of the exploration log at all, to be honest. It's a pretty standard "monster in a cave" horror story.
It also feels very expository: "Oh look, printing presses!" "Oh look, a river of fat! I bet it's clear underneath!" The drone camera viewpoint feels like a thin excuse to have the reader present in a 3rd-person narrative. The ending also feel more visual than textual, if that makes sense. Everything from "Agent Cooper becomes visible through the smoke…" on feels like the end to a horror film.
As a story, it's not bad at all, but I'm not sure it fits the article.
◾whether the whole things feels balanced
The article has 2 arcs. Arc 1 goes something like: slow reveal of the item, reveal of the horror of the item, reveal of the things it creates, pursuit of suspect, dangling mystery. Arc 2 is the entirely separate exploration logs: descent, discovery, monster, death, dangling mystery/fade to black.
I could be wrong here, but wouldn't monitoring work better? Is a mobile task force needed. Plus, if these books are being printed in an underground Meat-Cave, why monitor publishers? It's not like copies of this book would have made it through a review board at Penguin.
The book's "life cycle" could use a little more explanation. Have you considered making it a single print run or a non-recurring item, where the goal is just to find the existent copies, not track down newly generated instances?
I preferred the formatting of the 1st version. Something might have gone awry during the copy/paste over. I think your second version has a bit missing around
And the formatting at the start of
Agent Cooper's investigation notes
is very odd.
◾my use of Catalan slang in the logs - does Rey feel plausibly authentic?
As, characters, sure. In a Tale, fine. But in the main article?
The article feels like "The Creepy Meat Cave: an Agent Cooper and Agent Rey story, now featuring Catalan Slang and Banter" Sorry if that's a bit harsh. Why, in the documentation for the containment procedure for a book, are we getting stories of badass OC characters exploring a cave system, except for the fact that it's a story you want to tell?
The photos for the "recovered materials" actually detract from the story. They're clear, bright, and not at all obscure or creepy.
I really enjoyed the excerpts and the book description. You could also add some details on containment (biohazard!) for SCP-AAAA-2 instances.
I would consider ending the entire article on the line
Other personality changes appear to be permanent.