I have another question regarding your script: Is there a specific reason you use NNEDI2 instead of NNEDI3?

nnedi3 is nnedi2 with improved predictor neural network architecture and local neighborhood pre-processing.

It COULD give better results but is slower. These are screenshots from an interlaced source, I don't know how well it will work on the GOUT:

NNEDI2 vs. NNEDI3 (no source unfortunately)

To counter the slower speed, we could utilize the video card's GPU power for processing NNEDI3 in this OpenCL rewrite: http://forum.doom9.org/showthread.php?t=169766

Depends on your video card of course. May I ask which specifications your GPU/CPU has?

That build also seems to support more colorspaces (when using the nnedi3x script with Avisynth 2.6 mentioned in the wiki) if I'm not wrong. Perhaps that could reduce one or two conversions, I have yet to understand all of your script.

I will have to acquire the NTSC GOUT (I only have PAL) and try this out, but I wanted to share the information so you can take a look at it already.