Just a quick follow up in case anyone finds this in a search and has a similar issue...
The white scab/scales appeared again on his head but in a different location after the shed following the above photos. He just shed again last night and everything is back to normal on his head. Here is his head skin from last night. View attachment 288537View attachment 288538
Not sure what is causing it but he didn't seem out of character while he had them.