Love the concept of this as a response to the title. Looks really nice. I'd dispense with "timeline" and "event triggers" as this info can be gleaned from the reality descriptions themselves, and makes more sense in that context I think - I was initially a bit confused reading those sections but everything made sense when I'd read the whole thing. You have the intro for general background / structure overview anyway.
As written this is a nice length for a single session adventure, but it also feels like it has a lot of potential to be expanded, and would be easy to drop into a campaign pretty much anywhere. I wouldn't hate to see a more overtly aggressive alien threat somewhere, but appreciate there is already plenty going on for a single session. The IMPLACABOT is excellent / horrible and cats and their enmity with the Plesiarch are very pleasing.