There are a two different CIE LCh color spaces: they are cylindrical samplings of CIELAB and CIELUV, similar to how Oklab can also be sampled with cylindrical coordinates
The comparisons with CIELAB and CIELUV are using LCh coordinates. That’s how hue and chroma predictions are made using those spaces.
The comparisons with CIELAB and CIELUV are using LCh coordinates. That’s how hue and chroma predictions are made using those spaces.