Histograms of the input SB_e (left panel) and the input R_e (right panel), colour-coded according to their detection by eye and in the MER catalogue. Here, N_ontSEARCH is the number of MER sources found by using the search radius R_ontSEARCH for the cross-match. It is worth noting that the dwarfs in MER catalogues and those with N_ontSEARCH > 1 are also detected by eye. In this plot, all the dwarfs (nucleated or not) are included. In complement of this plot, Appendix C provides a SB_e-R_e map of detection rate. Finally, in Appendix D, we also provide the histogram of ⟨μ_ontI⟩ as defined in Euclid Collaboration: Marleau et al. (2026).