I'm going to follow your suggestion and just put the extra effort into distributing a pre-built image.

That sounds good 🙂
If you feel the need is important, I do have a hack in mind, it will be doable once we have support for entrypoint "-c python_code_here". But since this is still not available I believe you are right and build an image would be the easiest.

A note on the docker image, remember that when running inside the docker we inherit the system packages installed on the docker, so if you change python packages there will not be any need to build a new image :)