Is there any subpixel text rendering implementation that avoids color fringing to such a degree I cannot see it, or not? It's certainly there on both Windows and Linux.

I don't know if such rendering is commonplace, but I know for sure that imageworsener handles this correctly for downscaling images. Check out the option `-offsetrb 1/3`.

https://entropymine.com/imageworsener/subpixel/

I see there is some interesting stuff in the parent page as well, thanks :)

I don't know what you can and can't see, but I could not tell the difference between gray scaling a screenshot and not, on my mac back when they still used colored subpixel AA (unless I zoomed in on the screenshot).

Yeah it is a subjective and configuration-dependent thing for sure.