What I'm talking about is in the lines of SnarlyGribbly's EZSkin, but more generic.

EZ skin leaves the original textures intact, but changes the shader tree settings for skin like qualities.

I'd like to see something like this for other materials than skin only. Say fabric, wood, asphalt, tree leaves.

Load an old prop or set, keep the original textures, but improve the shader settings at the push of a button. A generic shader for wood leaving the wood texture but altering the way light interacts with it, etc. Create such a shader once and then be able to apply it to all other props and sets. And release commercial sets of these add-on shader settings.

I'd consider that very useful.