Kaizoe: There is, as of yet, no way to travel non-linearly through space. You might want to argue that any kind of curve make it non-linearly, but the only way to make non-linear travel is to just appear for no reason at a spot without having moved yourself in to the area beforehand. If you ever travel non-linearly through space, you also travel non-linearly through time, because if no time has passed as you passed through an area, you haven't traveled through time, but then you also actually have traveled through time as no time passed when you traveled through the two spots in space without going through any of the space between the two spaces.
If you ever travel non-linearly through space, you also travel non-linearly through time, because if no time has passed as you passed through an area, you haven't traveled through time, but then you also actually have traveled through time as no time passed when you traveled through the two spots in space without going through any of the space between the two spaces.