The noise in the Gizmo mode adds implicit displacement to vertex positions. But the curvature mode doesn't measure from vertex positions...it's generates curvature info from vertex/edge/face adjacency info...so there's no way to add noise like that because position data isn't considered.
That said, you can always just layer some noise on top as a separate selection type, that subtracts from your initial curvature selection. Ex: a noise texmap selection.
That said, you can always just layer some noise on top as a separate selection type, that subtracts from your initial curvature selection. Ex: a noise texmap selection.