Adobe guys: You have a bad variable access, bad pointer, or something in Camera Raw with regard to Color Noise Reduction...
If I have color noise reduction turned off (set to 0), I see this:
And in fact it converts to just what shows in the preview:
If I bump the Color noise reduction slider up to 1 with the Color Detail slider at 100, I get this wonderful DeBayer smoothing in the preview:
But alas, this is what comes out in the conversion:
The smoothing shown DOES in fact match if one sets the Color Detal slider to 50 at the middle of the scale:
This is just an annoyance, but it does take some trial and error to see what you really want the Color Detail slider set to.
By the way, I notice that the jaggies come and go seemingly randomly when the Color Detail slider is at 100 and I move the Color slider. I suspect you're reading the wrong or random location for Color Detail, or maybe have an overflow/underflow condition somehow.
Object oriented programming - fraught with gotchas.
What you are seeing is a limitation of the diagonal/curve behavior of the current demosaic method on colored boundaries, combined with the (preview-quality) color noise reduction with specific settings. It is the demosaic strategy that is at fault here (and is why you see these results in the final exported result).
Thanks for the info.
Just something to keep in mind when you're looking at what to fix for the next release.