Candidate X-ray-to-optical flux ratio limits (black) are compared to those of the known XDINS population on the German eROSITA sky (magenta, optical flux values are based on Kaplan et al. 2011) and the most prevalent contaminants of our search, namely M dwarfs (red, taken from Magaudda et al. 2022), cataclysmic variables (blue, selected from the Ritter and Kolb catalogue (Ritter & Kolb 2003) and the open CV catalogue by Guillochon et al. 2017), and AGN (green, taken from Liu et al. 2022).