Actually, Mange was doing everything right in this case, he was trying to fix whatever Paradox did to models and clothes after the Iberia update. For some reason the clipping became worse, even though the point of this whole Paradox overhaul was to fix clipping issues. It seems it excessively relied on the body shapes being close to vanilla, which broke bigger body shapes that we need for our mod.
Yes, I personally only like female weight gain and prefer men to stay slim. The way I made it work is that after you pass the “dynasty of fat women” decision you have an option to also make your house “a dynasty of slim men”, which disables physical trait influence on male weight. The reason I did that is because after you breed increased appetite into your dynasty, both your men and women become fat, and staying slim as a man becomes impossible. Also fertility decreases by a ton because both genders are now fat. So this option helps prevent that. I tested it well enough imo, but if it doesn’t work for any reason, I’ll look into that.
Also there are now game settings that adjust the rate of weight gain and the influence of traits on your weight. Borabora was asking for a way to make the weight gain more like in the old versions of the mod, and these settings should help achieve that.
Honestly, I don’t think there’s a way, unless Mange does something that would help with that. And even that would not necessarily prevent clipping for very fat people. I also use the undress mod, and in the nude form fat people look fine. Maybe I should make a setting that automatically undresses all superobese people.