Shot Dunyan= Green Taylor Simms
Is it possible that Shot Dunyan seeded the Green Taylor Simms that first went back in time? We know that Simms only adopted that name some time after having travelled back in time.
Echo Lawrence: Whether she believed it or not, he raped her, that girl had a child she named Irene, and the man, now calling himself Green Taylor Simms, disappeared for another thirteen years.
Green Taylor Simms askes after he goes back in time if anyone has invented boosted peak technology yet, and in the final chapted Echo Lawrence speculates that Shot Dunyan would be involved with this if he time travelled.
It would also explain why Shot's egg said Green Taylor Simms on it.
And... Shot Dunyan disappears in the middle of a car crash, according to the piece at the end of the book.