>>8369902I was going to say the ER mold was just the Siege skeleton with a different shell, but looking at them now, they actually appear to have remolded almost every part. I think the only ones that might be similar are the hands, elbows, crotch, and hip parts. It's quite a large amount of work for something with so similar a transformation.
That said, I'm pretty sure the head balls sizes will be the same size. Would be weird to change that of all things. Then again, weirder stuff has happened, so we just need to wait for Wave 2 Deluxes to finally come out god damnit.