Expansion timescales for Case-A contact systems formed through the expansion of the accretor star with M_1,  i = 5.2 − 20.0 M_⊙. In models marked with filled red (blue) squares, the accretor expands on its thermal (nuclear) timescale prior to the onset of contact. The colour scheme is the same as in Fig. 7. The dark blue solid line indicates the division between Case-A and -Be systems.