Regarding Unitful-compatible types in the second part:
It’s really great that you highlight the fact that the type should go beyond the machine type.
However, I am deeply convinced, that azimuth and elevation are two totally different types (one defined for 360°, the other for 180°, one defined as the deviation from a plane, the other as a deviation from an axis, one spanning a cylinder when rotating, the other a cone when rotating).
But this is all beyond the point for your example. You could avoid potentially misleading the readers of the tutorial by switching your example to polar coordinates. There, you can focus on the core of the relevant problem.