If anyone does this but finds their camera turns off after 30 minutes (and if you can't fix it by updating the firmware or changing settings), try this:

connect your camera via hdmi AND usb, then:

> brew install gphoto2

> gphoto2 --summary

You'll know it worked if you see your camera make/model show up.

That one --summary call is all that's needed for my Canon m50 to stay awake forever! I'm not sure if it works for other models, but when I figured that out I was super happy :)