Fig. presents the VSC-suppressed rate constant using the FGR expression (Eq. 16) under different Rabi splitting Ω R values and the cavity lifetime is τ c = 500 fs. Here, we consider the molecule coupled inside (a) a 1D FP cavity and (b) a 2D FP cavity. Fig. presents the results of k/k 0 value using Eq. 16 (dashed line) or numerically evaluating the frequency integral related to the photonic DOS (solid line), see Supplementary Note 9 for details (numerically evaluate the integral in Eq. S126).