KiCad's Specctra exporter writes wire coordinates with six significant digits, so past 100 mm a track that starts on a pad centre arrives up to half a micrometre off, and Freerouting only connects a trace end at the exact pin centre. On the 20 PCBench reference-routed boards, the router started with 5,586 unconnected items on boards that were complete in KiCad. With the 1 um snap it is 427, and unrouted-after-one-pass went from 941 to 90. The KiCad bug, #25850, is confirmed upstream but not fixed in the versions people use.