That's unfortunate. When I got a slider functional in CAS but it wouldn't change anything in live mode, I suspected that there was more going on.
Truth is, I can change the appearance of child sims in CAS using the Obscurus Slider after I updated it through the modding software, but none of the changes are updating in live mode. The screenshots I took are depicting what I got working. I guess the key word is that the Slider is Functional in CAS.
If my memory still holds true, the software detected things out of date and I updated it. Loaded the game and could make changes in CAS. Everything I do in CAS doesn't update in live mode, including the vanilla preset bodies.
As for the modding software I used, I used ts4 morphmaker 4.5.2.0 and simply loaded the mod into that software. The slider then worked in CAS as I think it appears it was intended.