As can clearly be seen from the color samples taken from the two renderings in which the conversion to sRGB occurred before the PS edit, the colors are different from the version in which the sRGB conversion effectively occurred at the end (thanks to the soft proofing).
What i noticed on both sRGB versions is that red hair band is clipped badly even i remove saturation completely still no visible texture on hair band just same color, while ProPhoto RGB version it's not clipped and when de-saturated shows texture.
You can process in sRGB, but then there may(will) be issues when exporting into wider spaces, e.g. AdobeRGB.
My reply was to your comments about 16-bit capability, which is not at all exclusive to wide gamut spaces.
From what i find online mostly its information
guides how to choose HDR TV and they they do recommend TV's with HDR + WCG (wide color gamut) rather than just HDR. Pretty convincing to me.
IMO with photography editing its same logic, why should i use color gamut from SDR TV era (sRGB year 1999) when working on HDR/High Bit Depth photo's, better i take advantage of additional data WCG (ProPhoto RGB year 2013) provides.
To me using sRGB with 16bit photos is like using "Only Web Colors" option in Photoshop color picker so to say,. Of course its not so dramatic difference, but i like to push my edits to the limit and less colors could possibly mean mean more artifacts/clipping.
Pretty good explanation here, if you consider for editing purpose.
You can get clipped colors in any colorspace, and just about any image can be presented without clipping in sRGB.
Images generally start out as raw data. Raw data does not contain RGB color information in the traditional sense. For the vast majority of cameras, the raw data contains only luminance information for each pixel. Each pixel is behind a red, green, or blue filter. The software that processes the raw data considers the luminance data and the knowledge of the color filters in order to convert the capture to an RGB image. There are other factors that affect the conversion, including the ISO setting, the selected color temp, saturation settings, and a variety of options that affect the tone curve.
One might ask the question "given a certain raw pixel value, what color should the resulting RGB pixel be?". The answer is often "What color would you like it to be?"
Consider a taking a photo of a model holding a neutral gray card. What color should the pixels over the gray card be? Should they be a neutral gray to reflect the fact that the card itself is gray? Perhaps they should have an orange tinge to reflect the fact that the photo was taken at golden hour? What color should those pixels be if the photo was taken at noon in bright sunlight? What color if taken indoors under tungsten light (should it be gray like the card, or have an orange tinge due to the tungsten lighting)?
The answer to all of these, is that it should be whatever color you want it to be. Most of the time, the photographer wants to create the most aesthetically pleasing photo.
Now let's bring this back to sRGB and color spaces. When the raw data gets processed, the software needs to decide what color each pixel should be. More often than not, there is no single "right" answer. If you have asked the software to produce an sRGB file, it can fit all the colors into the sRGB colorspace. If you ask the software to produce an AdobeRGB file, it has a wider pallet of colors to choose from - however, that doesn't necessarily mean you want it to use all those colors.
If you have clipped colors, then you can choose to process to a wider gamut colorspace, or you can choose to process with different parameters. A lot depends on your goal.
For instance, if your final product will be an sRGB file, then one can make a reasonable case that you should be working in sRGB.
The advantage of working in a wide gamut colorspace is that you have the option of using additional colors. It's like having a wider range of crayons to choose from. If you want one of those colors, then it's very help to have the option. If you don't want/need any of those additional colors, then the wider gamut provides absolutely no advantage.
The disadvantage of a wide gamut colorspace is that the gamut may be much wider than the gamut of the final output device (be that a monitor or a printer). That means that at some point the wider gamut colorspace will need to be mapped into the smaller gamut of the output device. Unless you are handling that conversion, you have no control over it. Suppose the colors in your image easily fit into sRGB, but you deliver them in a ProPhoto RGB file. The final rendering may involve squeezing the entire ProPhoto colorspace into sRGB. These can cause the colors in your image to shift, even thought it was unnecessary.
The other disadvantage of a wide gamut colorspace is that the addressable points in the visual colorspace are spaced further apart. This means that you are more likely to get banding if you edit the image. A common strategy is to use 16 bit per channel files instead of 8 bits per channel. These files are twice as big, but you have so many addressable points, that even though there are further apart in a wider gamut colorspace, there are still close enough together to avoid issues.
