actually the idea is that nature cant operate at that scale.
the thing about planck units is they are extrapolations that end at single planck length that has some problems just with basic geometry, as well as a supposed instability of a planck space spontaneously collapsing.
a planck unit volume must take a form that has dimensions of single planck units and pack together so that no smaller spacings are created. it cant be a sphere, at best it can be some sort of riemannian tetrahedron or triangle.
it would be conveinient if that level was a 2D plane, but it still has issues.
something that cant be reduced would be the only entity, all other things are assemblages of that entity, the problem of variability occurs, if you can observe at the scale of absolute fundamental structure, how can difference occur?