Taking primary through pinch points is good practice, but it can only influence other road users' behaviour. It may make an attempted overtake and squeeze (or worse) less likely, but obversely, it means driver impatience can manifest itself in other unpleasant ways i.e beeping, tailgating before the pinchpoint, passing too closely afer the pinchpoint etc. Changng the dynamic of the situation by taking an assertive position is not a win/win when dealing with pinchpoints. If traffic is not heavy, sometimes the path of least resistance is to back-off before the pinchpoint and then you do not have to take a strong, blocking position on the approach. It also shows other following motorists that you are prepared to defer and facilitate the progress of faster moving vehicles and, if you do need to move into primary postion further down the road, they are more inclined, in my experience (particularly if you thank them with a wave/nod/smile), to treat you more considerately.
fair comments and something that I do on one of my commuting roads with 5 consecutive pinch pints.