[Primus]

i was once working on the interior of an opera, and the client wished for a special kind of stucco texture for the tiers.
no chance with tiled textures, so everything was uv painted.

now the size necessary for the textures of the entire interior could never fit onto a single map, and i had to create 5 materials for the different parts of geometry, also for painting performance reasons.

you can imagine going through changes in such a material setup...

But it seems to me what you are looking for here are master/child materials, rather than textures alone? You have 5 materials with identical settings, only the maps change, right? Change the master material and the children update? Otherwise I don't see how the ability to instance the texture editors settings would help much.

For my understanding ... master/child materials, this scenario you mentioned here. Is that actually possible in the current version ? Or , do you think of a possible feature in the future ?