Sure. Take a look at how the Data Flow sample is implemented. https://gojs.net/latest/samples/dataFlow.html
Or have separate templates that call the same function to result in the same property settings and GraphObjects, such as in the FlowChart sample. https://gojs.net/latest/samples/flowchart.html – see the
But note that it is not possible to actually share references to the same GraphObject in multiple templates. Each template must have its own copy of GraphObjects in its visual tree. That’s why all those functions called for multiple templates construct and return their own objects.