@parametricmonkey1 Yes. So Revit keeps the “Shared Parameter” definitions in the Revit model once they are added to the model from the text file. If you have a shared parameter file that does not include a parameter that is in your model, you can select that parameter in the Project Parameters window and “Export” it to the connected shared parameter file. This will add the parameter definition to the text file and you will be able to see it in the Shared Parameters manager window. This is quite common when receiving families with shared parametes from other companies.
RIR creates a temp shared parameter file, creates the parameter, adds to the Revit model and then reconnects the original shared parameter file to the Revit model.
This is primarily to avoid messing up the original shared parameter file.