bake curvature from mesh
Right now the curvature is generated from the Normal Map which leaves artefacts and gaps. Since a lot of smart materials are driven by curvature maps, curvature from mesh would be a crucial addition to painter's bakers.
I completely agree ! Converting normal map to curvature will always get gaps where UV's are split at hard edge.
Also, as curvature holds both concave / convex information, a curvature from normal map wouldn't have any concave information from low poly intersections and you must rely on AO to compensate for this.
So yeah, curvature from highpoly is a must.