Mass-dependent time of flight (TOF) since ejection from the disc for US 708, once for proper motions as obtained by Geier et al. (2015) and once for proper motions as published by Gaia DR2 (Gaia Collaboration 2018). The preferred model with M_US 708 = 0.3 M_⊙ is highlighted in green. Note that the counter-intuitively shorter TOF at similar mass obtained for the slower space velocity of the 2020 data set is a result of the shorter distance traveled to the disc-crossing point. This shorter distance, in turn, is derived from the reoriented direction of travel as compared to the 2015 data set (see Fig. B.2).