Add placebo comment labels
Related to the other "disengage" feature suggestions, I think a "placebo" comment label could also potentially help the culture of the site. What I mean by that is perhaps adding some comment labels that have no effect, or only an effect for the person that applied it. e.g. A "Disagree" comment label, that has no effect whatsoever, or perhaps makes the comment collapse (like a "noise" labeled comments), but only to the user that applied the "disagree".