OK - I’ve made notes for my future reference. This makes sense, although I’d not thought about the gamma implications. Thanks for the explanation.
One sort of related question about this tool (I’m not sure what the color wheel’s “official” name is 
) :
What’s the difference between saturation applied via the sliders at top vs. on the side? I’m not asking about input vs. output (I understand that) but rather either of them vs. the vertical slider. Does the vertical slider affect only the saturation intensity of pixels changed by color wheel adjustments, while the other two are image-wide (either masked or not)? Somehow that seems basically the same thing in many cases.
Thanks again.