Left: marginal posteriors on the location, scale, and mixing fraction (relative to an isotropic component) of the truncated Gaussian distribution in tilts given five different mock catalogs. Lines in the joint marginals only enclose the 50% credible region for clarity. Right: PPD in spin tilt for the same analyses. The true astrophysical distribution is isotropic (black, dashed line). We highlight the mock catalog which returns the strongest support for a peak in red; analyses of four other mock catalogs are shown with other colors (green, orange, purple, and gray). For comparison, in blue we include the LVK’s analysis using B-splines (B. Edelman et al. 2023; A. G. Abac et al. 2026b).