Twist profiles for Q_best set. (a) Comparison of the in- and outbound profiles for the three cases: the Lepping FR extension [ − R₀, R₀] (black, case 1), the in situ FR extension [ − R_inf, R_inf] representing the eroded FR observed at 1 au (blue, case 2), and the non-eroded FR extension [ − R_sup, R_sup] representing the possible initial FR (case 3). The in- and outbound profiles are represented with solid and dashed lines, respectively. (b) Comparison of case 3 (R_sup boundary) with the results of Fig. 10 in Lanabere et al. (2020). Their SEA results for in- and outbound (in orange) and the Lundquist model with R₀ = 0.12 au (in green) are included.