Parameter.CreateProjectParameter not working

The inbuilt node ‘Parameter.CreateProjectParameter’ doesn’t see to be working.

When I run this graph nothing happens - no error, no results.

I’m not feeding a value to ‘groupName’ because I want to create a family project parameter, not a Shared one. (When I do feed a string to ‘groupName’ I get a ‘null’ result.)

The description says:
Create a new Project Parameter in this current Revit document for all applicable categories.

It says nothing about Shared Parameters

Also the list of parameter groups from the ‘Select Builtin Parameter Group’ node doesn’t include common groups like ‘Model Properties’, or ‘Dimensions’ or ‘Other’. Why not?

missing Group name

Check Project Parameter.

Group name is for Shared Parameters, not required when (or makes any sense to include) when creating Project Parameters.

Why did it get included?