So, here's an interesting experiment:
First, I tried Device IDs of 0, 1, 2, 5, 7, 11, 13, 99. Yes I did try 0. Nothing changed in terms of the audio - still scratchy.
Then I removed AppleALC and left Wintergreen (can't boot without it - get black screen) and Lilu.
I thought this would mean no audio. But it didn't - I have my LG Ultra audio output, and while it's far from perfect, its major league better than with AppleALC. 90% of the scratchy audio is gone, (but, its not gone completely). I do get audio halts (brief), but it's so much better, I am going to leave it this way, at least for a while.
I'm wondering what this means? I have to assume that the audio is coming from this: SSDT-X299-HDEF.aml, but it's interesting that the only output I have now is the LG Ultra HD monitor. I would have thought I would have no audio, but that's not the case. (note: the USB audio codec output listed below comes from an external device, not an internal device).
This makes me think that AppleHDA is the real problem. Hmm.....
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