PYNQ seems to be about connecting to a PC, interacting with the server, running scripts… nice to explore and experiment. But, when it comes to developing a stand-alone embedded python solution to do something without humans around, are there any tutorials/ documents?
Yes, you are correct, there is a focus on development. If you want to deploy, you can export your Python code from a Jupyter notebook to a Python script (check the file menu in Jupyter).
You could then just schedule your Python script to run automatically at boot.