This means… The default setting disables the core AgX mechanism (the matrix), and the default setting is not one of the presets… I think that’s problematic, the default should be one of the presets.
The attenuation to white is essential for AgX. With the current default, the matrix is turned off by default, that means the colors never attenuate to white by default. This is very problematic, considering many people don’t really touch the primaries tab, they might never know, that they have been using a simply curve without AgX mechanism involved at all.