X-ray-to-optical slope anti-correlates with the UV monochromatic luminosity at 2500 Å. SDSSJ08 (orange circle) is consistent with the best-fitting relation of Lusso et al. (2010, dashed line) and Nanni et al. (2017, red dotted line). The z > 5.7 X-ray-detected sources from Nanni et al. (2017, restricted to z < 6 and ignoring SDSSJ08), Vito et al. (2019) and Pons et al. (2020) are shown. The empty triangles denote upper limits from undetected sources (same colour code as detected sources). The grey density scale shows a sample of 2685 XMM-Newton-detected z < 5 SDSS quasars (Lusso & Risaliti 2016). The contours show the eFEDS normalised, sensitive area derived from synthetic power-law spectra at z = 6 with Γ = 2 and Galactic absorption. We note that CFHQJ14 (black point) tends towards flatter α_OX values than X-ray-detected quasars at similar UV luminosities. Its α_OX was computed from the luminosity reported in Medvedev et al. (2020b).