This is a very unsettling and intriguing idea. There are multiple ways to approach using this module with the teasing information given and the open ending has me wanting more. I see this as an exercise as a group solo game, where each player journals the crews experience seperately and the GM (as the OS) put them together, revealing not the authors but the characters experiences as the group wanders the final dungeon.
Great work with creating the atmosphere and inspiring curiosity in both players and game masters.