It would be really cool if the Ruler tool, or similar, could work in 2D previews, and sample the scalar value. For example, what is the default scalar range of the Voronoi Diff Scalar? Or the Perlin 3D Scalar? It would be cool to be able to sample this and other scalars.
Additionally, this information for these scalars would be nice information for the wiki. Like right now I want to do a precise soft maximum and minimum scalars on voronoi diff but it's hard to tell what is the "ceiling" of the scalar by visually seeing where the scalar is unaffected by values.
If this is too crazy to add to the GUI maybe something simpler, like a debug function which takes a input, and just spits out the minimum and maximum scalar range in text when the shader is open.