This is fun! I have one thought about the whole time-travel thing, but I don't know how to do a black bar in case it's actually true. Also, generally speaking, since time is fluid and expansive, going back wouldn't change the jumper's reality when they returned. They already exist in one thread, and since they are themselves they'd have to return to that thread and anything they've done in the past is creating a different thread.
I'd guess generally, anything they do won't be done when they come home. Or something like that. Or, all of our realities exist at once and we can choose which reality to return to, or even mix and match to suit our wishes. As the Buddhist belief's go, we are always rising and falling away, but our consciousness remains the same.
I just gave myself a migraine.
Also, panties.