We had Jack neutered around 6 months. I noticed he did start lifting his leg and very soon after that, he was neutered. He is funny - in the house on the pee pads he will squat like a girl and when he goes outside, sometimes he squats and sometimes he lifts his leg. It is very entertaining to watch because I think he misjudges and almost falls over because he lifts it so high.
Good luck in your search. My next pup will be a Biewer.