I decided to make the pre-req Python package installation the user's job. I've included instructions on how to work around the dependency problems in the documentation, and the plugin itself will display a pre-req status screen showing if the required package was installed or not.
It wasn't too hard - I used a try; catch on the package import, and in the exception handling I set a setting indicating if the package import failed. The UI then picks this up in an observable and displays the status.
If the Python pre-req isn't available the plugin still loads and shows a different icon in red.