I just added a new demo showing how the BVH can be used to speed up extraction of edges along clip planes for things like CAD applications. Using the BVH the clipped edges can be generated in real time on the 2 million polygon demo model.
Check it out here:
https://gkjohnson.github.io/three-mesh-bvh/example/bundle/clippedEdges.html
And thank you again @prisoner849 for the suggestion!