I really like the flowchart room map – though the readability thereof could be improved. Maybe having corridors plotted out and doors marked? It's a bit unclear what the connective tissue between each room is. But it still being in three columns is really nice.
I like how constrained this is, it's a clear in-and-out. At the same time, this feels like it's unlikely this would challenge the characters? The failing all SAN saves would add... 3d5 stress, so 9 stress? With average SAN saves, maybe 6 stress. Though as a part of longer campaign the gain from a quick oneshot would be meaningful, of course. All to say, might want to add a panic save and some more stress, maybe.
But overall, a great way to add substance to the body mods, expanding that part of rules beyond "you can buy them." Useful and usable.