Whether or not the load required a larger OCPD is something only you could answer. But I think what he meant is that on larger ampere ratings, there is a tendency for these older design breakers to not clamp onto the bus as well as they should. Some of this is attributable to poor designs, some of it to the fact that often, these breakers are installed in panels they were not actually designed for. The "BR" line within Cutler Hammer is short for "Bryant", an older company that became the residential arm of Westinghouse, who made breakers and panelboards that were supposedly "interchangeable" with others, like ITE / Siemens / Murray and even GE to some extent. When Eaton bought out the Westinghouse distribution product lines, they absorbed the Bryant lines, but called them Cutler Hammer "BR" series to distinguish them from the other existing Cutler Hammer product lines (which were NOT interchangeable).
Bryant was always considered the "low end" of those interchangeable product lines; their quality was never that good, which is one reason for their demise I suppose. But the installed base was huge, too big for Eaton to ignore, so they still sell them.
