Growth rates of unstable regions for different rotation and Brunt-Väisälä (BV) frequency profiles, shown in the background color scale, are displayed for the stars considered. The type of shear-driven instability (e.g. SMRI, MGSF) is indicated in each panel. The BV profile exhibits a narrow peak corresponding to the hydrogen-burning shell. Its position defines the reference radius, r_b. The reference width, w_b, is defined as the radial distance over which the BV frequency decreases by an order of magnitude from its maximum at r_b. Left panels: Star A, top:B_Z, 0 = 1 kG, w_d = w_b, r_d = 5r_b. Bottom:B_Z, 0 = 100 kG, linear rotation profile Ω(r). Right panels: Star F, top:B_Z, 0 = 1 G, w_d = 3w_b, r_d = 2r_b. Bottom:B_Z, 0 = 100 kG, w_d = 5w_b, r_d = 2r_b.