It only starts out 1-dimensionally, it continues to evolve on a standard GoL grid.
Then, importantly, it collapses itself back down to a 1-dimensional copy of its starting representation, but translated.
Specifically, after 133_076_755_768 steps, the 1-dimensional pattern reoccurs translated by two pixels. On skimming the thread I haven't determined if that shift is parallel or perpendicular to the line.
I think it has to be parallel by symmetry.
Can it leave other bits behind after it moves?
By definition of a pure spaceship / glider, no it can't. If it emits persistent "exhaust" that's a "smoking ship"[0].