@henryL I think you're mixing up some concept here. By analogy to Revit, Dynamo and Marionette do not serve the same purpose as Revit's family editor. They are tools for programmatic/parametric design and geometry generation and general programmatic control over a project.
I think that ArchiCAD has something much, much better than any of the competitors. It's called Rhino. Rather than reinventing the wheel, and making it a suboptimal wheel in the process, Graphisoft entered into a collaboration with Rhino folks and we now have a live bridge between ArchiCAD and Rhino. This is waaaaay better than Dynamo or Marionette. In my opinion of course
😉 Time will tell how advanced and integrated the bridge becomes.
Now, when we talk about a visual GDL editor we mean a tool for making loadable 3D objects, like chairs, cars, that sort of thing. Like Revit families. I don't think that this sort of thing can be farmed off to a 3rd party app because it requires far too great a level of integration and access to the internals of ArchiCAD.
Pushing the boundaries of local time/space continuum since 1972.
Archicad 26 | iMac (Retina 5K, 27-inch, 2017) | 4.2 GHz Quad-Core Intel Core i7 | 24 GB | Radeon Pro 580 8 GB | macOS 12.6