Evolution of 16 M_⊙ star in LMC composition considering no winds (left) and no composition changes (right). The colours and labels are the same as that of Fig. 1. For 16 M_⊙, the winds play a subdominant role in stripping the envelope, and completely switching them off only prolongs the PSS phase by ∼1.3 times. On the other hand, in the hypothetical scenario with no composition changes due to burning (in particular H shell burning), the PSS phase would be much longer, by ∼4.7 times, illustrating the key role of shell burning in determining the evolution through the PSS phase. The green dots appear so close in the right plot, showing that the contraction happens very slowly as compared to the default scenario.