I am primarily a stills shooter, but I can see how overheating can be disappointing. I think these numbers are from a cold start.
I wonder how it would work if I had the camera on and taking photos here and there, and then switched to shot a short video
Very good question, that's what I'm curious about as well. The numbers being listed in ideal conditions make it a little concerning for run and gun video.
I'll likely never use the 8K function except for some studio stuff here and there, but it's the concerns about overheating in 4K60p that are the issue. I was hopeful of being able to not have to carry around the GH5 with me, but it looks like I'll have to wait for that day to come.