To illustrate this:
The mesh option has no effect.
The size of the primitives are fairly random from what I can tell. And scaling them has no effect. So you can’t really tweak collisions at all.
if I delete that sphere you can see the effect it had.
You can delete primitives, add and move or rotate them. Even use capsules or boxes. But you are left with the sizes given and the result is not adequate.
Is there another way to add collisions for the hair?