I’ll keep this short and sweet. Imagine the current material tool mixed with the one in Hammer.
-Material positioning; Rotation, Scale, and X Y tweaking
-Material Blending; Choose two materials, use a slider to set make one or the other more visually dominant.
–This would be used for adding a shiny matte material to one with texture, or blending two textures together.
-Perhapse some advanced material switching with a wire controller, this is secondary.
Colorization is unnecessary as there’s already a tool for it.
Anything else is tertiary.