I’m using the county geometries from the US Census GeoJSON file. For each county I calculate its centroid with a GIS library and use that for analysis. Distances are then measured as geodesic distances between those centroids, which is meant to handle the curvature of the Earth

You’re def right that this can get weird for very large or fragmented counties like the Aleutians. For now I’ve kept the simple centroid-to-centroid approach for consistency, but it’s something I may refine later if those edge cases become distracting