Kronons really disliked how when you loot the books piles they disappear after you loot them, but the shelves/cases did not. He think it’s more immersive by having the book cases, and book shelves disappear after you loot them. Also makes the game harder.
Kronons can also make a version where none of them disappear after looting, but that’s a bit immersion breaking.
The forum topic of the mod is here.