It's called a 'heat ring', it's usually worse on the inside of the tyre.Tires I’ve seen driven absolutely flat never had a scalloped section out of the side wall, that’s a new one on me. This band is 12mm wide. It has melted the rubber and it’s wavy like the tread of a race slick is after super hard braking.
Tire is on front right.
I’m taking it to get new tires in a week or two anyway.