Evolution of the orbital distance and envelope ejection fraction f_ej for the MHD (thin lines) and Hydro case (thick lines). Shown are the orbital separation (blue) and the fraction of unbound material according to the kinetic, thermal and internal energy criteria, respectively in orange, purple, and green. The black dotted vertical line indicates the starting time of the magnetically driven outflows and the labels “P1” to “P4” represent the different magnetic field amplification phases identified in Sect. 3.2.