You don’t have to time travel, you only have to appear to time travel.
As an infinite set of possibility state expressions in an 11 or 12 dimensional structure composed of all possible states (all pasts, presents, futures) some of those states could (perhaps would) be states in which the information that is you seems to exist in it’s perceptual past, when in fact it is merely another version of the apparent forward progression of time that an expression of all states leads to, the only difference being that the state expressions surrounding “you” would set themselves to match say the 1940s on earth rather than a normative progression of states.
Since the expression of all possible (even the severely improbable) states means expression of glitch, rare, and unusual states as well as progression normative states - you appear to go back in time, but really it’s just state information expressing a rare circumstance.
The main problem people encounter is that they assume that they are connected to all “previous” state information. Imagine the state information for a time line being a film strip. The frames are not actually a part of each other. They are independent. However if those frames could each hold information about “previous” frames then those frames would experience an apparent progression of “time” even though they are still completely unconnected. It’s just that the state of the matter is set to give the appearance of time having progressed by the matter being expressed in a pattern which expresses the appearance of a “past” by containing the idea of “previous” even though time is a static structure containing various states. The effect is that you are the film strip and the audience.
Whatever the granularity of eternity, you are a static collection of possibilities - an infinite, but static collection of possibilities which seems to progress only because many similar states share the delusion of being connected.