To create a reference to a Constructor, in an external file:
Models that are externally referenced cannot be edited in the current drawing. This must be done on the source file.
If you want to open the model's source file, click the button Open Reference:
If changes are made to the models, it is possible to update this model by clicking the button Update References from the model's context menu or, to update all models, by clicking the button Update References from the context menu of the node Custom Sections.
Finally, if you want to promote the models so that they are part of the current drawing, click the button Promote References, in the context menu of the node Custom Sections, or if it's just a template to update, in the context menu of that particular template.
Note: On the one hand, the model must be referenced when network references are created, since the model creates the network devices. On the other hand, you can create a template file with styles and templates and then reference only the ones you need to use in the current project. So, if you want to revise such models, you can only do so in the source file and then synchronize the drawings using these references.