Good point, "the people who know you think you’re ugly" has a way greater impact than “people you know think your opinions suck”, especially since chuds tend to care a lot for physical appearance.

I'd advise caution in insulting someone's appearance though. Using it against working class people without class consciousness could turn them against the left, depending on how sensitive they are; and in the wrong social context the one making the insult could make themselves look like an idiot or buffoon.