NCS Colour INDEX for Photoshop 2023

But isn’t it untimately another company (like Pantone) that does not »feel« like being too cooperative with Adobe customers? 

Interior decorators and house painters will know what this is 😉

»NCS« didn’t ring a bell for me … but that does not seem to be surprising because despite being/offering a »global standard« it is apparently not targeted at the graphic industry. 

While I can see that this can be useful, I'm not quite sure it belongs in Photoshop.

Photoshop is built around icc-based color management. In that framework, Lab is the absolute reference. Lab is at the heart of all color management as the "Profile Connection Space". All other color spaces are defined against this. When you have a set of Lab numbers, the color is unambiguously defined, and can be accurately translated into any other color space - including monitor and printer.

So what you need is a reliable NCS to Lab converter. I would assume that even NCS is defined by Lab numbers.

Do not trust any NCS to "RGB" converters! There is no such thing as a universal RGB, only a series of RGB color spaces that differ in primaries, tone response curve and white point. sRGB, Adobe RGB, ProPhoto RGB, DCI-P3, any given inkjet printer profile, any given monitor profile - they will all produce different numbers from the same visual color. And vice versa.