Actually in my game in both sprites and CGs they're all covered up so not an NSFW issue rather I only have SFW haha :') There is not an ounce of explicit content throughout my Dahlia run sadly not sure why. They are always in clothing and undergarments. Unless it's meant to be this way? If it helps i'm on Dahlia's first CG and they were clothed.
The NSFW version features the first kiss CGs (these are all clothed), plus additional CGs that are fully R18. So as you play through the route, Dahlia's completely NSFW CGs will come up. There aren't any censored versions of these - these are simply removed when SFW mode is active. Sprites are the same in both versions, and you won't see completely nude sprites.