Have you realised Calman is locked to a 33^3 LUT size?

Most of the accuracy in a calibration LUT is decided before the LUT is uploaded.
ColourSpace can generate native LUTs at 1024³ and beyond on x64, then extract a smaller final LUT for the display or processor.
Generating well above the final size means oversampling, which gives a more accurate result than building at the final size directly.
Calman's engine is internally capped at 33³, whatever size you export.
A bigger container does not fix an engine that never filled it.

https://lightillusion.com/lut_size.html

Steve

LUT Size