What you are all calling a "vocal blob" to me at first sounded like Jon's voice breaking a bit when going high. Maybe the fact that the vocal track is different vocal tracks mixed in together creates that "blob". It does become very noticeable and now it gets on my nerves when listening to the song.... Maybe it's a minor jump in the vocal track, Shanks trying to change tracks withing the same note could produce that sound, maybe he liked the start of one take but the end of another....