Hi there,
I've been no longer active in Open Source or Open Content development/promotion for some years, mostly due to health reasons (Long Covid), but also some personal disappointments. However, one of the issues that are still important to me is the original mission of freieFarbe/freeColour (not its current incarnation). With respect to Inkscape and other FLOSS programs, the most important development is that after I resigned in protest, because they refused to honour an internal agreement to release all colour palettes under the zlib licence, they did it anyway, albeit much later (https://freiefarbe.de/en/licence/).
What does this mean? It means that Inkscape can now choose to include any of the more than 300 commercial colour palettes from the Open Colour Systems Collection 2.0 and, more importantly, both versions of the free and open Pantone alternative HLC Colour Atlas (standard and XL) in one of the formats supported by Inkscape (https://freiefarbe.de/en/thema-farbe/software/). I would, however, strongly advise against including all OCSC files. A reasonable selection would be the HLC and CIE palettes for the fF CMYK colour fan (as opposed to the much larger Atlas) and the HKS palettes, since HKS is still being widely used for signage in Europe. As regards the rest, you could either provide a download + installation opportunity, as Scribus currently does, or simply leave it to users to download and install the palettes they want or need.
With all of the fF content under the zlib licence, this should no longer be a legal problem.
I wish you good luck and success for the future!
Christoph