Finally, I decided to use both the "good mix" profile and the "good" profile. This means that while "good mix" provides better mixing capabilities, it's not sure that it will converge for every color, so it's better suited to be use with KisKSLCColorSpace.

The "good" profile always assure to converge into a reasonable reflectance spectrum, so it will work with both KSLC and KSQP. makedefault.* script are provided to generate the the default profile that are loaded with Krita.