HRD of the main-sequence evolution of the most massive models in our grid within the TS scheme without MLT++. The initial rotational velocity is 300 km s⁻¹. Initial masses in solar units are indicated next to the starting point of the models. The colour-coding shows the logarithmic mass-loss rate. Stars with M_ini >  250 M_⊙ follow a ‘down-stream’ of rapidly decreasing luminosity evolution and become helium-rich objects by the TAMS. A mass fraction profile of the outer 30% of the mass near the TAMS is shown in the inset, illustrating that they become helium-rich stars. The three most massive stars in R136 are indicated with symbols and the filled areas show uncertainties in their HRD positions according to Brands et al. (2022). Numerical smoothing is applied for visualisation purposes.