Kippenhahn diagrams for the models with α_ov = 0.10, α_ov = 0.2, and α_ov = 0.4, all with log(D_env/cm² s⁻¹) = 0 (panels a, c, and b, respectively), as well as α_ov = 0.2 and log(D_env/cm² s⁻¹) = 6 (panel d). The solid black line is the stellar mass. The green hatched areas correspond to areas of convection, the cyan hatched areas to CBM, the red hatched areas to semi-convection, and the yellow hatched areas to thermohaline mixing. The blue dotted line indicates the hydrogen-depleted core. The red and green dotted lines indicate the helium- and carbon-depleted cores, respectively. The colour scale shows the ²⁶Al mass fraction as a function of the mass coordinate and time.