I found the G3X Touch Installation Manual pin data for the GEA 24 GP ports to be conflicting and confusing so I decided to map the available pins directly to the connector drawings.
The attached files may be of use to anyone else who is planning to add signals to the GEA 24 interface. Available pins/ports are based on CC G3X schematic and have not yet been verified by inspection of the actual connectors. Please let me know if you see any errors.