The VSC-modified rate constant k VSC , expressed in Eq. 41 and its approximate versions in Eq. 43 and Eq. 44, are the key theoretical results of this work. The approximate expression in Eq. 44, although less accurate, readily provides an intuitive understanding of the VSC modifications on the rate constant. Under the limit of J eff (ω 0 ) → 0, k VSC → 0, the effect of the cavity will diminish, and the rate constant (Eq. 40) will be reduced back to the situation of the outside cavity. This limit can be achieved by three possible scenarios: (1) the lightmatter coupling strength η c → 0 (a trivial limit). ( ) for non-negligible η c , one still has J eff (ω 0 ) → 0 if there is a large frequency difference between ω c and ω 0 (see Eq. 14). ( ) when α → ∞, or the cavity lifetime τ c → 0 (see Eq. 32), meaning either λ c → ∞ and/or γ c → 0, both of which correspond to an extremely lossy cavity. We will revisit this simple rate expression when further analyzing the numerical results of the VSC-modified rate constant in the following sections.