Why are the South Nodes not included in the Aspect Grid or Natal Planets to left of the chart

This is deliberate that the South Nodes are not included in the Aspect Grids and Natal Planets.  The major aspects are covered by the connections to the North Node. Trine, sextile, square, and conjunction/opposition are all covered.

We feel that the North Node aspects are more important.   Plus, the conjunctions, oppositions, or squares are all covered:  conjunct NNode or “ square the nodal axis “ with interpretations for both N and S node.