Simulation details. Left panel: adopted relation for the redshift evolution of R_e, constant for z ≤ 1, and taken from Shibuya et al. (2015) for z > 1, together with the upper and lower limits within which R_e is extracted (light red area). The black dashed line shows the 0.070″ threshold – under which the source size is indistinguishable from the PSF – after the convolution. Right panel: resulting scaling relation, i.e. θ_E vs. F160W, compared to those from Bergamini et al. (2019, 2021a) and Caminha et al. (2019), in red.