Very nice. Did you try with more patches? The dE you get is quite high, so accuracy might be less than ideal. As a rule of thumb, everything above a dE of 2 is visible. See also Color difference - Wikipedia
About the manual editing of the .csv, I guess it’s about time to get that fixed … And maybe even make it possible to have a HaldCLUT2dtstyle script that does the magic without any user interaction.