Cosmological constraints in open ΛCDM from the mock sample of 20 lensed SN Ia systems with good time-delay measurements. Panels and labels are in the same format as in Fig. 8. The input values, shown in black, are recovered within the marginalised 68% credible intervals/regions. The combination of D_Δt and D_d makes the H₀ constraint relatively insensitive to other cosmological parameters, as shown in the 2D contours in the left panels.