Yes, rotating the pump can help in certain situations. As we are all a bit different, some may have different erection angle etc., so for some people the slanted part on your pubic bone works better.
I usually rotate one or twice in a session, to deliver a different kind of stretch.
It's about giving a different kind of stimulus from time to time; our bodies can adapt to a certain stress, so swithing your workout is important for growing.
One wouldn't pump the same amount of iron at the gym all the time, variation and building up intensity counts!