[Cin] Histogram plugin

I was rereading the manual about the Histogram plugin and there are things that I don't understand: 1- Is there no longer a frame interval averaging function (Frames button)? When was it taken out? Perhaps on this occasion? https://www.mail-archive.com/[email protected]/msg02691.html (moreover, the images are to be replaced) 2-I don't quite understand the concept of "Sum" instead of "max." The explanations are not clear to me. Can anyone clarify to me the behavior of the plugin with respect to Histogram Bezier, scopes and various color models? The explanation in the manual (section: Theory) is taken from here: https://www.mail-archive.com/[email protected]/msg01834.html