Average surface rotational velocities as a function of luminosity during crossings of the IS for 3, 5, and 8 M_⊙ models of Z = 0.002, initialized with a rotation rate of W₀ = 0.5. In the top panel, models without magnetic effects and models including magnetic effects are compared. In the middle panel, models with different values of parameters affecting chemical element mixing, f_c and f_μ, are compared. In the bottom panel, models with different efficiencies of mass loss (η_R = 0.4 versus η_R = 0.8) are compared.