Spectroscopic HR-diagram of the binary-stripped models explored in this work. The models are color-coded by the mass at core He-depletion M_He−dep (see Fig. 3). Each track is plotted from the end of core He-burning until the onset of Case BC RLOF (filled circle). For those that do not undergo RLOF, the plot is shown until the point found at 20 yr before the end of the run (empty circle). The track of model B13.5p6.3 is highlighted in black and shown from ZAMS. The He-stars in the Small and Large Magellanic Clouds analyzed by and Götberg et al. (2023) are also shown (black squares), and numbered as in Drout et al. (2023).