butcher ? I have enough light to saturate all raw channels sufficiently - where is any butchering exactly in a raw histogram posted ? ... and then a normal raw converter shall allow me to WB that as I want...
Enough signal in the different channels is not the issue with metameric color issues. It's the seemingly disrupted contributions between the Bayer filters that will cause potential issues, hence the 'butchering'. But that's probably not your original issue, because I presume that the CC pigments are chosen for their insensitivity to metamerism, and other converters do better (with a significant tint
and temperature adjustment) than ACR.
I see only a raw converter (some of them) issue... gel used will not create any additional metamerism beyond what was already present w/o it.
Only for well chosen combinations of illumination and pigments. Our digital camera sensors are not spectrophotometers, but rather tri-chromatic sampling devices, so color inconstancy and metamerism is always a potential issue when pigments are not chosen carefully. Again, this is unlikely to be the issue with the CC profiling with a tri-chromatic sampling device here, because other Raw converters do a better job.
But even with Capture One Pro V7 (example attached), while the overall color balance is more acceptable, it is not perfect (because the light quality was compromised with a Magenta/Pink filter which changed the demosaicing balance between color bands for specific colors, especially those crossing CFA filter band boundaries).