Line ratio and η-parameter profiles for the best fit PGC 28308 models. The dots show the observed values, colored according to the η-parameter going from blue at low η to green at high η. The size of each dot is relative to the size of the corresponding Voronoi bin. The solid red curve shows the best fit high-Φ_HOLMES model (χ²/ν = 156), the dash-dot magenta curve shows the best fit extreme-Φ_HOLMES model (χ²/ν = 167), and the dashed black curve shows the best fit model without HOLMES (χ²/ν = 175). The best fit values are h_zn = 1.2 kpc, f_V = 0.14, and log U₁ = −3.10 for the high-Φ_HOLMES model, h_zn = 1.9 kpc, f_V = 0.14, and log U₁ = −3.20 for the extreme-Φ_HOLMES model, and h_zn = 1.1 kpc, f_V = 0.14, and log U₁ = −3.10 for the model without HOLMES. The reasonable high-Φ_HOLMES model fails to reproduce the high η-parameter in the eDIG of PGC 28308, and a model with unrealistically high Φ_HOLMES/Φ_OB is required to do so.