Measurements of ⟨f_escξ_ion⟩ across redshift. Our constraints based on ρ_UV and Ṅ_ion are shown for two different M_lim (black). For comparison, we show measurements from the galaxy-optical depth cross-correlation (Meyer et al. 2019, 2020), direct detections of the Lyman continuum (Pahl et al. 2021), and indirect f_esc and ξ_ion tracers (Saxena et al. 2024; Rinaldi et al. 2024; Torralba-Torregrosa et al. 2024). The implications of the LAE-driven reionisation model of Matthee et al. (2022) as well as the models of Muñoz et al. (2024) and Davies et al. (2021) are shown in shades of blue. At z = 4, our argument only produces an upper limit due to the unknown contribution of quasars to Ṅ_ion. At z = 6, the measurement of Ṅ_ion becomes strongly dependent on the modelling of hydrogen reionisation, and our constraints should only be taken as a rough estimate.