Seconding a lot of the concerns already mentioned here.
The concept of parasitic timelines appeals to me, but the exploration of that concept here is weak. With Xyank's first transmission, you entice the reader with the excitement of a world-ending adventure. How did it happen? Who will survive? How will they deal with it? Then the first half of the offset is talking about parasitic timelines and what they are and how they work, but this is rather disconnected from Xyank's activities and the interesting story. Without that crucial contextualisation, reading your technobabble isn't very enjoyable. Xyank's message conveys to the reader that the world is fucked … in slightly more detail than before. I like the imagery of Dallas turning into metal, but there's not enough of this kind of thing to create a potent atmospheric piece of terror and awe. We get one more with the "buildings of flesh and bone melded into metal and plastic", which is a lovely aesthetic, but it's not quite enough. The third message explains how the Foundation received the messages a little bit and delivers more exposition but fails to develop the narrative in intriguing ways.
The final note is the most frustrating part. I get that you want a mysterious ending, but this feels incredibly forced. The ideas there aren't smoothly introduced or fully explored so this ending is not very satisfying. I was honestly really surprised to see that there wasn't another offset because this ends in an odd place where you haven't done a lot to make me care about these questions.
