Let's clear this post a little……tattoo and hairs are not a problem for poses adaptation cause they are just a textures! the problem in adaptation came with different body shape: a toned or talled (or shorted!) body, to be used need to make several adaptation of the whole poses we have, or we end to see the body of our partner trespassing ours and viceversa and that's not a so funny view. this is why Lover said we probably will never seen diferent body shapes in AChat.
I get what you mean, but in the early early stages of Playstation Home, before custom avatars were developed, they would release T-Shirts that were super-thin so it looked like you were shirtless and had abs, but really you just had a very well-drawn shirt on. Kind of like the street art that makes it look like theres a hole in the ground when there really isnt. So they could at least try something like that for muscle tone.