A good way to tell if the phimosis body mod is working is it's supposed to be sticking out of the main character's underwear to a fully visible degree in the standing portrait. If you maxed out on the phimosis penis body by the last stage. But it's remaining tucked into the underwear which I think isn't the correct way it needs to be displayed. I checked the Japanese version standing portrait and that's what I have seen I could be wrong but that's my take on the matter.