[ Della is visibly startled to be asked about this, and needs a moment to re-direct her thoughts. ]

Well, the train part is new. But my evidence was based on being told you can meet people from your past and future here - including your own self! I've met a younger and an older Alice Liddel, for example. Which goes into two parts.

One, there hasn't been any time-traveling paradoxical "never the selves shall meet" explosions.

And two, the future selves never mention "that time I went on a world-hopping train", nor do they mention anyone missing or gone for a long period of time in relation to it.