You missed that these extra volumes are NOT cloops - and that I actually don't want to have them automatically mounted. They are not joined into the unionfs mount, as they are, essentially, persistent over Knoppix releases.
Of course KK uses "your" mechanism for temporarily adding stuff to Knoppix releases. I don't need to remove anything, so it's not so useful for me with more overlays. Remastering is, essentially, collapsing overlays.