I've also been going for your bibliography and trying to see if any of those folks have anything on this. One of the problems with the Picts are the lack of direct evidence and the massive truckload of myth that surrounds them 😵‍💫

Not something I've ever really delved into tbh as they're quite a bit later than the ones I look at. But Gordon Noble and the uni of Aberdeen Northern Picts project would be a good place to start.