>>363829867
Unwrap the face to a second UV map, and then bake the texture from the old UV map to the new. This will result in an unmirrored face texture. This is not a particularly easy process, but not super tough either.
Alternatively, just make a second UV map containing the face and use a shader that supports decals or detail albedo and put a simple mole texture on there which will overlay the main texture.
Or easier, just select half of your face and assign it a new material, with a slightly edited face texture (containing the mole).