With the exception of an injury, docking is purely astetic.
that pup is FAR too old to have it done by banding, so it would have to be done surgically. He is not too young for anestetic, many vets do pediatric neuters, it can be docked when he is under for that. (I am assuming that your firend is not planning to breed a puppy mill dog)
The sooner the better though, puppies heal very quickly compared to adult dogs.
Inside me is a thin woman trying to get out. I usually shut the bitch up with a martini.