Around last year I was using some custom plugins for OBS, I haven't used Broadcast Box but I can pick it up to try sometime later.

> If that is still too heavy, what could I do to make it better?

I haven't picked it up yet to see whether it's complex enough to really need it but it has the same pain point a few priors did--being yet another service which I must configure via the browser and so it has to run an entire frontend for doing that rather than being able to do config files.

Broadcast Box can be configured via env variables. The frontend is also optional!

It is like RTMP where you can just do a URL to publish/watch. It does come with a frontend though.