Fizzlers are intermediate states that may form between white dwarf and neutron star densities during the collapse of massive rotating stars. This paper studies the gravitational radiation reaction (GRR) driven f-mode secular instabilities of fizzlers with angular momentum distributions h(mc) appropriate to the core collapse of massive rotating stars, where h is the specific angular momentum and mc is the cylindrical mass fraction. For core collapses that maintain axial symmetry, the h(mc) of the remnant reflects the conditions in the precollapse stellar core, and, thus, the h(mc) will resemble that of a uniformly rotating star supported by the pressure of relativistically degenerate electrons. Such an h(mc) concentrates most angular momentum toward the equatorial region of the object. The onset of f-mode secular instabilities in such fizzlers is affected strongly by the h(mc), whereas instability depends only weakly on compressibility. For a broad range of fizzler equations of state and the core h(mc), the f-mode secular instability thresholds drop to T/ ≈ 0.034-0.042, 0.019-0.021, and 0.012-0.0135, for m = 2, 3, and 4, respectively. These same thresholds with the Maclaurin spheroid h(mc) are T/ = 0.13-0.15, 0.10-0.11, and 0.08-0.09, respectively. The growth times τgw for GRR-driven m = 2 modes are long. For fizzlers with specific angular momentum J/M ≈ 1.5 × 1016 cm2 s-1 and T/ 0.24 (ρc 1014 g cm-3), τgw > 400 s. For these fizzlers, τgw τde, the deleptonization timescale, and GRR-driven secular instabilities will not grow along a deleptonizing fizzler sequence except, possibly, at T/ near the dynamic bar mode instability threshold, T/ ≈ 0.27.