Overall, one of the main conundrums of modifying chemical reactivity in a cavity is that while the collective coupling of an ensemble of molecules to a radiation mode and the resulting collective Rabi-splitting is a global phenomenon (involving all molecules spatially spread inside the cavity), a chemical reaction is a local phenomenon in that only one molecule undergoes chemical reactivity at a time which is largely dictated by the potential energy surface of the single molecule. Thus, whether or not the collective coupling to all molecules also translates to a local modification of the potential energy surface of a single molecule remains an open question. Ref. 195 has attempted to shed light on this issue.