OpenCities Map CONNECT Edition U17 and subsequent releases include the new Feature Definitions and Inference Rules dialog.
The Feature Definitions interface can be used to duplicate feature definitions en masse, functionality previously unavailable via the GeoSpatial Administrator the traditional interface for XFM Project feature management.
Warning: this workflow will attempt to modify the XFM project feature definitions and associated items. Be certain to backup your XFM project schema definition regularly and prior to use for the Feature Definitions interface.
To begin, launch an XFM Project map session from the Geospatial Administrator or your previously defined shortcut.
To launch the Feature Definitions and Inference Rules dialog, browse to the Map Admin workflow > Map Configuration group > Inference Features or use the ribbon search (F4) and enter 'inference...' :
From the Feature Definitions and Inference Rules dialog, select the Feature Definitions tab.
Navigate to the main 'Features' node:
Selection of the Features node will populate the Feature Details pane with the list of features available to the Workspace and Worksets.
From the Feature Details pane, select or multi-select features for duplication. Use the Copy and Paste icons, hot-key combination or selections from the context menu.
The pasted definitions will maintain the display name of the original feature, but the feature name will be incremented accordingly. The diskette icon appears to indicate that these changes have not been saved. 
To attempt to save changes back to the XFM Project definition, select the 'Save' diskette icon shown in the General Tools section of the dialog.
Existing sessions of the GSA will not reflect any saved changes in real time. Reload the schema definition to see your modifications:
At this time, help for the Feature Definitions and Inference Rules functionality is available only from within the dialog itself via PDF file.
To access the help. select the help icon in the General Tools section.