Prior volume of the astrophysical parameter space. Dashed lines demarcate the fiducial parameter values used to train the IMNN, 2D contours enclose 95% of the prior volume, and the points denote the 152 prior samples at which we computed the Fisher information for our summaries. Note that all units and log₁₀ factors have been removed for clarity; see the main text and Fig. 1 for reference on the units.