Posterior probability distributions (grey) of the five target parameters. Each column corresponds to a different sample drawn from the Clean group. The first column shows an example of an unimodal posterior distribution with a clear single peak (i.e. MAP estimate), which is the most common case in our results. The other columns represent degenerate cases where the posterior distribution of some parameters has a multimodal shape. In these cases, we divide the posterior distribution into two groups depending on the posterior estimate of the Phoenix library origin: a library value of 0 denotes Settl (blue shading) and a value of 1 denotes Dusty (orange shading). In each panel, we present the MAP estimate and the uncertainty at 68% confidence interval (u₆₈) in the text box.