Symbology as Application Messaging System
When working with software there is always something that can be improved, fixed or invented. In the meantime you need to get your work done. Sometimes the "work around" is the workflow. Sometimes the only way to get something done is to pre-process or post-process data using any of the tools you have now. For example, if you need to create a CAD drawing with blocks rotated in a different 3D planes the tools of ArcGIS simply can't do it. However if you use the GIS to leave a message on each entity that is to be rotated, a CAD-based post-processing tool can finish the job. Converting any CAD symbology to GIS tabular attributes is a similar function in reverse; CAD symbology is "post-processed" into tabular attributes using a look-up table or other techniques we've discussed previously. Using CAD symbology or things like AutoCAD Xdata to pass information along into the CAD drawing can improve the power of your GIS and CAD interoperability by leveraging your CAD tools to do CAD-like functions.
Consider adding Xdata to AutoCAD drawings, or hiding a value in the entity THICKNESS property, or hiding information in an entity LAYER name. Then write a simple AutoLISP, Automation, or other CAD Macro utility to find the entities you've tagged and make the necessary custom modification according to the information you included from the GIS. Use CAD properties to encode meaning, after all is the same technique you use when creating other types of meaning for cartographic representation. The difference here is that the symbology is used for a temporary message system. Once you have made the changes in CAD you can erase the "message" by resetting the property with your custom CAD tool.