If you go from A to B before the photons can, from B's reference frame you are arriving from the future with perfect knowledge of events that have not yet "happened".
The same thing happens with sound regularly. A thing happens, and we receive light before we receive sound. Some third faster thing that gets to us before light would just be some other thing.
The distance of travel requires time relative to both reference frames.
If a star explodes at A and I travel to B at 2x the speed of light to tell folks at B, so what? Some time has elapsed and those two frames are still chugging along with causality.
Maybe there's some physics I've not learned that makes this obvious, but I've never grasped exactly why violating light speed prevents entropy from continuing. Even if at two different rates.
If we perfectly timestamped everything happening on two sides of the world and sent a telegram at twice lightspeed from A to B, it would still arrive after it is sent.
If you start being able to travel >c those relationships immediately get impossibly and paradoxically twisted.
See e.g.
http://www.theculture.org/rich/sharpblue/archives/000089.htm...
Congrats, you have just traveled “back and forth” through time. To people in both the Point A and Point B reference frames, you have “seen the future” and acted on it.
Now, the Legbreakers aren’t stupid. Once they know someone is screwing around with FTL they’ll just hold bets and payoffs until light can travel. Yes, but… how do they synchronize their clocks between A and B? And how can they distinguish between a lucky person and a time traveler? Etc etc, ad regressum.
"Now" and "Here" as fundamental concepts only make sense inside a single reference frame. If you break the idea that information has a speed limit, then both of those ideas shatter into tiny little pieces.
That’s not time travel. You could get the same effect by just blocking the photons before they make it to B, and then traveling at conventional speed.