Turning below 500' does not breach the AIP. The AIP allows you to fly below 500' for take off and landing. It doesn't say that you have to be on a constant heading.
I was taught not to turn at any angle greater than 15^ when climbing.... I was also taught to turn at 60^ AoB at 250' on navigation exercises (with a bit more speed on, obviously)!!!
The FoB should read, words to the effect, avoid flying over the built up area by turning as soon as practically safe to do so. It could go on to list minimums for club aircraft, such as, min 250', max 15^AoB, min speed Best Rate of climb.
The FoB shouldn't make a pilot break the club rules to stay safe. It should give guidance on how to best achieve the goal.