Do you plan in adding freedom of choice for transformations (if there's any) of the MC and other NPC's bodies? Like boobs, butt, penis.
There will be no transformations like plastic surgery while playing.
But if you mean just skins/mods for characters - it's probably possible.
I can say for sure, main hero will grow the hair and develop his body through excersises.
Also have plans to change the clothes of heroes while progressing the game