This is the historical record of the highest I2C-bus error count observed for the IOM during a specific past sampling window, preserving a burst of bus errors the live stats table no longer reflects. It is the field most useful for confirming a short-lived burst of bus errors tied to a specific past event, since averages alone can hide a brief spike. For example, checking IomI2CErrorsMax from historical entries around the time of a suspected card reseat would show whether that action triggered a temporary spike in bus errors.