I was assuming castration too, but like you, I don't remember that at all! And I read a few books and articles quite recently on Henry IV and the so-called investiture controversy, and I'd think I'd remember!

I'm intrigued that this is how a Byzantine writer presents the tale,

Agreed, it is interesting that this is how the Byzantines, gougers-of-eyes and removers-of-noses, tell it. ;)