I love using visual mods, it gives the game a better expirience. but some people think that visual mods are the same as speed hacks or whatever. Can i use luigi skin mod in my runs? or even the s e x y shirtless mario? it literally changes nothing, but the apperance.

I feel like that wouldn't be allowed. Even if you say it changes nothing, but the appearance, if a mod is used, you wouldn't know if it changed something else. To prevent any change, I'd say that it shouldn't be allowed at all.

After some research about it I can say that skin mods are permitted. SD/Luma/titles/TITLEID/here(Hex)/romfs

Any other sort of modification to the game with Luma3DS will not be tolerated.

And yes, I agree that shirtless Mario is smexy af.