I think any kind of hard clipping approach which takes each pixel independently is going to necessarily create some significant artifacts, though as the example

I think any kind of hard clipping approach which takes each pixel independently is going to necessarily create some significant artifacts, though as the examples here make clear, some directions of clipping work better than others. The most important part to preserve for the image to look reasonable is lightness contrast, as when it gets crunched away the image loses visible detail, and the better methods demonstrated in this post manage to save at least some lightness contrast. But all of the methods here end up blowing out / compressing away chroma contrast in some regions where it existed in the original image. What I'd like to see someone try is do is record the relative lightness and chroma, and (adaptation/context dependent) color relationships from the original image, and then try to preserve those to the extent practical even when bringing out-of-gamut colors into gamut. This will necessarily require modifying in-gamut colors to some extent as well. This is what good Photoshop users do when they manually adjust the color of an image from one display medium to another, but it involves some amount of careful conscious choice and skill.