Found a map of overland flow in the planning case for the new active travel network for the two new schools (aka Fife Learning Campus) - at https://planning.fife.gov.uk/online/files/7CBD9725C6B7697E97ED30EFCA884431/pdf/22_01125_FULL-20_-_OVERLAND_FLOW_POST-DEVELOPMENT-3232071.pdf

Case ref is 22/01125/FULL. It confirms my suspicion that the flow is west to east, so I've updated OSM accordingly and removed the fixme.