That may be, but I don’t think the casts that people notice for various cameras are a white balance problem, and consequently white balance is not the right tool to fix them.
To summarize,
- all cameras need a color correction matrix,
- adding one requires specialized equipment (a chart) and knowledge (to process this chart)
- this is apparently so tricky that no matrices were added in the past 7 years,
- lacking that, people can figure out a preset by eyeballing photos for their camera, but it is unclear
a. how much these generalize to other light circumstances,
b. if not, how to automate the process,
c. where to put them in the pipeline.
Again, I am aware that I could just get a color chart for best results. But I am not after that level of fidelity because I am a hobbyist. I just want to get a linear mapping (a matrix) that gives a reasonable starting point.
I will now experiment and will probably find a preset that removes the cast. But the broader issue is that I see no systematic way to share these presets and avoid duplicating the work.