I'm just doing my PPL exams and really am not getting along with this blooming wiz wheel... the crappy 5!
Use of a circular slide rule is not mandatory for PPL / LAPL exams. But it's really a very simple device.
However, an assessed understanding of the triangle of velocities certainly
is required!
When the next iteration of the UK PPL exams is released, you can expect clarification of practical requirements for aspirant PPL / LAPL pilots.