I think its time to give up here.
Yes, I think so. You keep reiterating the same things and my responses also have become repetitious. Your ability to see another point of view is limited if it does not fit into your preconceived ideas, which are usually but not invariably correct.
You can't define a color gamut without a color space. They clearly indicate encoding of the data after a color file is produced using what you are calling demosaicing.
First of all, we are not trying to define the color gamut of a camera, because it has none, as you have already pointed out. However, if you extended the analysis into the deep infra-red and ultra-violet a gamut would emerge.
The original set of debates started because YOU questioned that a Raw file was Grayscale. Then you accepted it was Grayscale (because it is).
Your memory is rather selective and defective here. I did not deny that a raw file was gray scale, but I also pointed out that an RGB file is also gray scale as per Bruce Fraser's writings. Please refer back to post #11 in this thread. I have not changed my opinion. The raw file is gray scale because it records only luminance, not color.
The channels of an RGB file are gray scale for the same reason. The difference, which you don't seem able to grasp, is that both of them contain color information. Once we know what the channels of the RGB file represent, we can generate color. By the same token, once we know what the gray scale pixels in the Bayer array represent, we can also generate color. Demosiacing is not necessary to generate the color. It was Jeff who went off on that tangent.
A monochrome file can have a color space if it contains color information that, when properly decoded, defines colors.
Furthermore, I merely stated at the outset that raw files lack a color space is debatable, which this thread certainly has proved. To paraphrase Bill Clinton, who said, "it depends on what the meaning of IS is", it depends on what the definition of a color space is. I have yet to see your definition of what constitutes a color space; lacking this, we can go nowhere.