I can only give information on the first Q:
No display device works in the YCrCb (component) color space. If you convert RGB->component, you will force an RGB->component->RGB conversion. Conversions from one format to another are normally a bad thing (some cause data loss while others introduce noise and/or non-linearities) and you are imposing 2 where there was none.
I'm guessing Extron builds an S-video->Component transcoder.
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Huck