The foundational code for armpit hair is already in, likewise hair around the asshole depending on bush level. Ron stated in the Discord that his intention is to have them included 'officially', without relying on a modder to do it. The bottleneck is the art. Because so much core art is still unfinished, paying the artists to include hairy armpits and assholes that are basically only important for one customized hair setting is down a good ways on the priority list. It WILL be included at some point and upgrading your support level would indeed 'help' as any increase the art budget is going to gradually expedite some of the more niche art aspects like hairy armpits, but it's also important to politely mention here and in the Discord that you're interested in those features. The more public interest shown, the more likely they are to get attention. But in any case, they're on the slate for the future regardless.