I know this has been done to death on the other thread (and I've lightly touched on it before), but since you seem to still use some avisynth in this project and there is concern about red tinted faces...

AviSynth's built in Tweak filter: http://avisynth.org/mediawiki/Tweak has the ability for you to isolate a color (say the reds) and then adjust the saturation for just portions of it you want.

For example:
Tweak (StartHue=80, EndHue=135, MaxSat=80, MinSat=10, Sat=1.20)

These are just numbers out of my butt, but what it does is this:

Start/EndHue selects the reds (80-135) (you can narrow the range if some reds are weaker than others).

Max/MinSat selects only reds that already have a saturation between 10% and 80% of maximum.

This allows you to prevent low level reds that might be errors from being boosted or reds that are already strong enough from being oversaturated.

Now just reds between 10-80% in strength are increase by 20%.

Probably some trial and error needed, but it should let you give the red levels a strong boost, but avoid oversaturation skin tones.

Just a thought. (My inability to demonstrate this further is from my lack of reference sources, and mild color blindness.)