GoPro

Pros

• If it's for YouTube and social media... you could get a couple of GoPro or similar small cameras and mount them inconspicuously, but with a good view, ahead of time.
• Does he film himself on a phone? GoPro.
• Get a shot from above and behind to show the back of DJ in foreground and audience out beyond (could be a GoPro or something fixed and rigged).
• I like your setup, I would just had a really super wide thing like a go pro crammed in the ceiling (if possible) for that occasionally over the top view.
• I only use chin or chest mount with an Insta360 x3 in good weather and a Gopro or other flat camera in wet or muddy conditions.

Cons

• action cams look like cheap stuff and the videos often show yellowy blurred faces
• Dji and insta360 seems to be doing much better than go pro
• Great camera… if he is into that type of thing. I’m not. I had a GoPro and realized I just don’t want to spend my day videoing, and want to focus on skiing. When you are skiing the camera often ends up angled similarly to the angle of th...
• Anything that has a major advantage to your phone in that price range will be for a pretty specific use, like a GoPro
• I've tried a GoPro and hated it, the t5i has a great microphone for what I do.