There are renegade Vau in the tabletop game, as well as Vau seeking their own approach to the prophecies that drive their race. "War in the Heavens: Hegemony" talks about Soldier caste Vau who have rebelled against their mandarins, as well as clutches (birth families) that evidence insanity. There is also the option that renegade members of the Dau'kedalir or Tla'lr Voama councils are conducting their own operations in the Known Worlds. This is less common during the Pax Alexius, but was more common during the Emperor Wars.

Also remember that the Vau Hegemony is made up of many races, some of which maybe active in these ruins, but we only had enough art for the base race :)