Maximum mass M_TOV of nonrotating NSs (top panel) and the minimum spin parameter χ_2.5 of pulsars with frequency f_2.5 (bottom panel) as functions of the high-density symmetry energy parameter J_sym. The currently observed NS maximum mass ﹩M={2.14}_{-0.09}^{+0.10}﹩ M_⊙ (68% confidence level) of MSR J0740+6620 is shown in the top panel. The arrows indicate the conditions for GW190814's secondary to be a superfast pulsar.