I got involved with a local DJ event shortly before the pandemic doing lasershows, and we ended up having to go online immediately thereafter. I had some experience with OBS from using it to composite stuff for video calls (pre-pandemic), so I offered to help run an online version. And then I had to figure it all out.
The way we end up doing it, DJs run their own sets at home (from different countries), then stream to an RTMP server I run on GCloud. I pull those feeds from home and composite them with transitions to the next DJ, then stream to a single Twitch channel. I had to teach myself not just the tech part (which was okay, I'm used to tech), but also figure out how to coordinate DJ transitions in real time with them, while MCing introducing the next DJ and simultaneously crossfading the audio and triggering the video transition. There's a lot of "Okay, 5 minutes to go, you're live on the audio mix. Start when I'm halfway through your introduction text, since there's 2-3 seconds of latency. I'll give you a live monitor feed of the stream audio in real time via Discord, use that as your cue. Aaand that was DJ foobar's amazing set! Coming up next we have " Sometimes it works better, sometimes it goes a bit wrong, and it's definitely not something I'd ever done before :-)
And DJs had to learn about cameras, compositing, audio capture and avoiding ground loops, etc, as well as the whole OBS side. I have a whole tech doc I send them with the OBS-related info, and we do test runs where I check that their audio/video is decent, their connection to the server is good, they have the A/V sync set properly, their audio level is good... Some other folks in this area have put together more general documentation on the audio setups and whatnot.
Also sent in a few patches to OBS, including one fixing a years-old unacknowledged bug that would silently kill audio in streams randomly after a few hours, depending on the exact setup. That one killed one of our shows 3 times and I vowed it'd never happen again. Turns out it was an infamous bug in the DJ restreaming community... that the OBS devs had always maintained was user error...
If anyone's interested in the details of running this kind of event, here's a presentation I gave with 3 other folks from the community: https://www.youtube.com/watch?v=5lHn73MsE7c