Upper-level populations for the adopted line decisions. The vertical axis is ﹩{\mathrm{log}}_{10}({{ \mathcal N }}_{u}^{{\rm{tot}}}/{g}_{u})﹩, where ﹩{{ \mathcal N }}_{u}^{{\rm{tot}}}﹩ is the total population in upper level u inferred from the integrated line flux. Leo P has no retained uniform X1D line and therefore has no plotted upper-level population. Markers are accepted X1D detections, with error bars combining the empirical correlation-aware flux error and the nine-refit half-width. No target has three accepted X1D detections, so no effective-excitation slope or intercept-derived mass is fitted or displayed. The bars exclude absolute MIRI calibration, distance, extraction-area, and extinction systematics; these would primarily shift all points for a target together.