As for the seed ship against Triarian worlds and tracking Triarian pathways, I suspect a seedship would only follow to find that they are somewhere completely different, go back, and then turn to a different, non-Triarian pathway. As for the seeds working in that temperatures, they would probably just redevelop a couple Seed Ships to reterraform the planets, though for now, the Triarians are completely safe, being untrackable in some way, and with seeds unable to do anything.