A suggestion to improve tools texture / material artists have at their disposal: allow, via script, the ability to animate or alter specific underlying maps / channels. Examples of this include:
Allowing for JUST the Normal Map to be scrolled / animated via the texture animation commands
Allowing for JUST the Red Channel of the Emissive Map to be scrolled / animated via the texture animation commands
Allowing for JUST the Alpha Channel to be scrolled / animated via the texture animation commands
Allowing Alpha or Emissive to have their strength controlled via script in PBR Materials.
Coupled together, these would drastically increase the flexibility of Materials without introducing such advanced systems such as custom shaders
Along with this, include minor modifications to the scripting system to allow these to select either the U or the V, as opposed to having to wholesale rotate the texture, thus preserving some integrity of the orientation.
None of this should imply or provide greater (or lesser) access TO the texture, merely the aspects in question, thus preserving intact any permissions.