The Battle of Twilight Gap happened loooooooooooong after the Clovis Bray projects during the Golden Age; Elsie could not have been around to mourn Ana's death, and then submit herself to the Device. Ana was among the first 30 to enter the Device, and predictions from these device participants supplemented the directives from the warmind that led to making the Exodus Project. Another part of the Exodus Project was creating Exos, frames that existing human consciousness would be forwarded to. Elsie would become exo here and she [i]could[/i] endure the collapse, but there's nothing here that suggests that she can time-travel as the exo stranger does. Those that entered the Device only envisioned various future timelines, and we're not actual participants in such. With the Hyperion theory, albeit just seeing the inlet view of some unknown rabbit hole, Chioma Esi is still more likely to be the exo stranger.