See the supplementary material for the details and further analysis of (1) the impact of cavity bath parameters on the damping of system dynamics; (2) the impact of
bath characteristic frequency on reaction dynamics; ; (3)
the impact of the light-matter coupling strength on reaction
dynamics; (4) infrared absorption line shapes and rate modification profiles in the single-molecule limit; (5) the importance of higher photonic excitation manifold; (6) the impact of various noise level
in collective coupling regime; and (7) the impact of dipole orientations.