Left: predicted f_esc, Lyα-Lyα EW₀ space for different E(B − V) (contour levels) with our grid model (see Sect. 3.3 and Appendix A) and comparison with fits and implications by using Eq. (6) (right). We find that increasing dust extinction drives f_esc, Lyα down for a fixed EW₀, with data at z ∼ 0−2.6 hinting for lower dust extinction at the highest EW₀ and higher dust extinction at the lowest EW₀, but with the range being relatively small overall and around E(B − V) ≈ 0.05−0.3. Right: predicted f_esc, Lyα-EW₀ space for different ξ_ion (contours). We find that while increasing E(B − V) mostly shifts the relation down, increasing ξ_ion moves the relation primarily to the right.