Modify the __main__.py Generated Script in a Python Binary (Zip)

[taytayallday]

I'm trying to understand how building a python binary as a zip works. I know that a main.py gets generated, which sets up a bunch of symlinks, then creates a temprorary directory in /tmp. It's been a challenge trying to pin point where in rules_python the creation of main.py happens. I see the template file for it, but I cannot modify it and have those changes show up when I rebuild the python binary... Is there any docs about how this works?