Comparison between the expected K_X for our sample of high-redshift AGNs (assuming the M_BH and f_Edd estimates from M25) for different spin values, and the observed lower limits from the X-ray non-detection, shown as triangles. Our models are shown with solid vertical bars spanning values expected for different spins, ranging between a_• = 0 (upper bounds, implying higher bolometric corrections) and a_• = 0.99 (lower bounds). The local scaling relation is shown as a red line, with the shaded area corresponding to a 1σ uncertainty (±0.26 dex), and the local observations by Duras et al. (2020) as grey points. Colour bars extending above the corresponding observed lower limits (shown in the same colour) indicate the existence of spin values consistent with the current Chandra non-detection.