There’s actually a cheat for that! I only found out about it recently, but if in the command line you enter “traits.equip_trait trait_Breasts_ForceOn”, it’ll add a breast texture to the active Sim. The downside is that it adds a bra to that Sim in CAS, but I’ve been able to remove it by… um… I’m actually not sure, I have so many mods installed I’m not sure which one did it. But once I figure it out I’ll update.