How could I identify the polylines of intersection, from the own meshes resulting from the corefinement using CGAL::Polygon_mesh_processing::corefine()?, but without having to use additionally CGAL::Polygon_mesh_processing::surface_intersection(), for example, what repeats the intersection calculation.
Would having the edges in both meshes sufficient?
If so, you can use the named parameter edge_is_constrained_map to mark the edges that are at the intersection. If you don't want to iterate over the edges of the mesh to collect them, you can write a property map that will collect them (IIRC, put is only called once per halfedge).
If not, it should be possible to get it but not with the public API.