When the thread has taken it to the point of which type of cinematic material is on each DVD used for spectral comparison then I know we've hit gold; I'm not surprised Ken has taken us there too. :-)

FWIW: I also have a Thomas Duplex, used it with vanes just about fully closed and never experienced fogging with either MCC110 or Emaks graded papers. However, I didn't use it 100% of the time because it was just too bright for my 10 by 16 by 12' (ceilings) garage darkroom at the time. When I did use it I used it in addition to 2 ceiling banked red LED safelights. I did not remember seeing any kind of fogging as a result of this safelight.

I did use the included filters (they're translucent red) at all times - just that the vanes were sometimes slightly open. I never used it without filters.