Unused Visgroups in Kleiner2

[WillARing]

I found 2 unused Visgroups in Kleiner2 that reveal new areas, has this been documented before?
(Don't mind the missing textures, I'm using gmod hammer because worldcraft will just crash when trying to open a map)

[VALVe_installer]

In addition to the room with the teleport, there is also a piece that previously appeared only on the demo_matgallery map and a piece of the subt map