Cosmological constraints in flat wCDM 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. When the dark energy equation-of-state parameter w is allowed to vary, significant parameter degeneracy between H₀ and w exists, which weakens the constraint on H₀.