That said, I've been using the Django channels project (https://channels.readthedocs.io/en/latest) to push notifications to browsers. It's simple and works well, and I believe there's still some argument about integrating it into Django's next major version. (I guess we'll see.)
Basically you'd swap gunicorn out for Daphne, the asgi server that channels recommends in its docs, write a consumer or two in Django that trigger on db signals, and add a websocket to project and build pages so users could see live build status. Maybe a separate per-build view to tail progress if you really wanted to go crazy.
Not sure if you had considered it, just a thought. Ignore me at your leisure. (Though it's an argument for requirements in a venv - pip-tools's pip-sync makes it easy to swap libs in and out :D)