In a discussion following SUG, we were trying to come up with a way to handle the issue of GLTF Overrides setting properties "all or nothing" in cases where override properties were not set, and the problem of needing to know what those properties were, combined with the issue of the simulator lacking the actual values from the material.

Here is a solution that seems workable:

If the material asset is included within the object's inventory, allow us to fetch its values using llRequestInventoryData. In this way, creators who intend to alter these properties can choose to include the material asset and sample the properties as needed, allowing for lots of new functionality to restore appearances and to fetch properties where no override was specified.

This would also solve the problems discussed with overrides.