Ionising photon production efficiency (ξ_ion) as a function of the observed UV magnitude. Lines represent the mean of the five runs with different seeds for each model; shaded areas represent the range between the minima and maxima shown by the 16^th and 84^th percentiles, respectively. Points show observational data as marked (from Simmonds et al. 2024; Llerena et al. 2024; Begley et al. 2025). The crosses at the top right corner of the upper panels indicate the average error on measured magnitudes and ξ_ion as estimated by Simmonds et al. (2024).