DeltaGen 24x: question on Assignment Tables to replace materials in a Library

Hello, I've been playing with different query possibilities to use Assignment tables to replace materials in a scene. Basically, I'm trying to replace existing materials in a scene Library with new materials from an External Library. At the moment, I can only do it with materials that are already assigned to an object, using query object.lookname MATCHES "material name", but I would like to also replace the materials in the scene that are not assigned to any objects. Is that possible?

Also, I noticed that the Assignment files do not retain a connection to external libraries, so if I close my file and load it again, even with the external library opened, it loses all of the looks connections on the right column:

 

Thank you!

Jorge