Also sorry I keep posting, but I just noticed the difference in wear on the cam retainer plate, the bad wear is on the phaser side not the cam side:
Given that I am almost positive this is the stock GM retainer plate and stock phaser, I wouldn't think there would be a significant hardness difference, but maybe the cam phaser bearing area is extra hardened. Either that or it's getting significant cam thrust load backwards towards the firewall. Or maybe this is just normal?