a seer of void can conceivably navigate the furthest ring for... obvious reasons. would a seer of space be able to do the same? i vaguely remember someone saying that only a hero of space or time could map out a path in the furthest ring

Hard to say, since ‘Space’ isn’t exactly what’s going on in the Furthest Ring, nor is ‘Time’, but it may work. Really though, any Seer may work.