Just a collection of ideas Ive had whilst using the new Material Editor.
Dragging and dropping a texture from the Content Browser to the Sampler should assign it.
For me this static bool could be useful in alot of debug respects on Blueprint also, in piping information directly through nodes to test their feedback. Its somewhat of a probe node because the real input gets pushed through over the top.
Result Preview, collapseable. Only for the Result Output.
Material Editor and Blueprint could share variables and functions panel, this would make the experience more cohesive over the two editors. It is understamdable that materials not provide access to custom structures, I do recommend a clear difference in the editors so that creating functions for either it is not confused. Types should be easily recongizable though as vector2/3/4, bools and floats(scalar) are commonly used in all areas of the editor.
Color as Objects on the Content Browser, just like textures we could use colors in a sampler. Color (palettes) themes could also then be made and saved as objects. I find this workflow similar to existing workflow rather than having a special case for color. This could open the door for graidents, curves etc to be used in a similar method on the material editor.