Hierarchical Spatial Hash Grid fails because it applies variance test independently per position, discarding quadtree's parent-gated filtering and adaptive sparsity

An alternative data structure (Hierarchical Spatial Hash Grid) fails not because it precomputes positions but because it applies the variance test independently per position, discarding the quadtree's parent-gated filtering and with it the adaptive sparsity essential to ES-HyperNEAT

http://arxiv.org/abs/2608.24480v1