Changes in the precisions p = σ_x/x (top row) and most likely values (bottom row) of initial mass (left column) and age (right column) when assuming a uniform M_ini-prior instead of the Salpeter IMF prior distribution applied in our default statistical model (the changes in most likely values are defined analogously to those in Fig. 8, i.e. Δx = x_uniform−x_std; x_uniform and x_std, and p_uniform and p_std denote the most likely values and precisions for a uniform M_ini-prior distribution and our standard prior choice, respectively). The observables are effective temperature and luminosity, and the precision ratios and relative differences are with respect to the precisions and most likely values when neglecting correlations (cf. Figs. 5, 8a, and b). For more details, see Sect. A.