Emulator accuracy across the cosmological parameter space, represented by the median reduced chi-squared (χ_red²) values of the test set predictions across 2D cosmological parameter spaces. The χ_red² values for the void size function are shown in the upper panels and those of the void density profiles in the lower panels. The void size function emulator is accurate over the entire parameter space, while the void density profile emulator is accurate except at low Ω_m values.