Top : transmission and emission spectroscopy metrics as a function of planetary density for the transiting ND sample, shown as black circles. The black diamonds highlight two benchmark ND planets for comparison with TOI-333b, which is marked by a red star. All TSM and ESM values were computed homogeneously using system parameters from the TEPCat catalogue. Bottom : TSM and ESM plotted against the effective host star temperature. The colour scheme and symbols follow those described in the top panel.