TOS Clarification:Third Party Program

[Halivel]

His issue with the character model mods was primarily due to the nude mods, which can get both Unit III and SE itself in significant legal trouble due to their rating, and the game may even be required to have the rating raised if they become too publicized. So again, if you use them, keep your mouth shut, don't post modded photos on your social media, and you will have no issues.

Clarifications here:

which can get both Unit III and SE itself in significant legal trouble due to their rating

Not due to the game rating itself but because in some countries this stuff is outright illegal no matter what age rating you slap on the cover.

and the game may even be required to have the rating raised

I said this so many times at this point that I feel like a parrot, but: the game doesn't have a consistent age rating to begin with. US: 12/13+. Germany&New Zeland: 12+. Rest of the Europe: 16+. Japan: 15+. Russia: 18+ (originally 16+, raised).
They can and they will raise age rating when and where needed.