I prefer to put it between the UAT and the pump. This keeps the wear and tear of fueling and defueling pressures off the pump and its seals. I have had a few pump leaks in the past, and it was always on the pumps where the shutoff was downstream from the pump.

BTW, you can see the leak coming, as the first symptom is an air bubble forming in the line between the pump and the UAT when you are defuelling.

Of course, Wayne makes the best point. It has to go somewhere easily accessible, and that is the first consideration.