Hi,
Here are some thoughts regarding this issue:
In the output node, I used the "copy" factory to generate output objects and add them to the scene. This was the workaround I found to bypass the limitations of the GeomObject.clone() method when cloning sub-objects.

I tested both the clone method and the copy factory on a grouped object; while they preserve the original object's name and style, the "parentObject" and "groupIndex" are not maintained. I could not find any method in the API to push an object into an existing group, and I am unsure how the "Assign Selection Here" menu achieves this.

I hope Michael has a hidden or undocumented method for this.

To select a specific group, I think we need a "Select Group" node.