Phase of the He subflashes of the evolutionary sequences in the log T_eff − log g diagram (grey and pink lines). Coloured points correspond to models with excited modes and the colour coding shows the minimum e-folding time for each model. Evolutionary sequences in pink lines have their pulsational quantities listed in Table 3. Also shown for comparison is the location of the known He-rich hot-subdwarf pulsators LS IV-14°116 (Randall et al. 2015), UVO 0825+15 (Jeffery et al. 2017), and KIC 1718290 (Østensen et al. 2012). The upper panel also shows the models discussed in Sect. 4.1.