I did not look in any of your links in detail. But I had to check on creating Geometry Nodes with Python some time ago as well:
It worked fine but finding some documentation was not trivial. Also I am not sure how stable the Python interface to Geometry Nodes will be in the upcoming versions of Blender…
In short: It is possible to create Geometry Node setups with Python but things can get complex very quickly. At least that was my experience. If I have to do it again I would check if it might not be easier to create an Asset and put that in place with the help of Python.